Distributed unit (du) measurement and event reporting in disaggregated base station

ABSTRACT

Aspects relate to measurement and event reporting from a distributed unit (DU) of a disaggregated base station to a central unit (CU) of the disaggregated base station. The CU can configure the DU with a measurement configuration associated with at least one value to be obtained by the DU and a reporting configuration for reporting the at least one value to the CU. The measurement reports can be sent by DU periodically or the measurement reports can be event-triggered based on the reporting configuration. In addition, the measurement reports can be UE-specific or DU/cell-specific. The measurement reports may include random access channel (RACH) reports, uplink measurement reports, radio link protocol (RLC) reports, medium access control (MAC) protocol reports, and other types of measurement or event-based reports.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present Application for Patent is a Continuation of pending U.S.Non-Provisional Application No. 17/236,946 filed on Apr. 21, 2021, whichclaims priority to and benefit of U.S. Provisional Application No.63/013,987, filed Apr. 22, 2020, and assigned to the assignee hereof andhereby expressly incorporated by reference herein as if fully set forthbelow in its entirety and for all applicable purposes.

TECHNICAL FIELD

The technology discussed below relates generally to wirelesscommunication networks, and more particularly, to techniques formeasurement and event reporting within disaggregated base stations.

INTRODUCTION

In 5G New Radio wireless communication networks, resources may be sharedbetween access networks and backhaul networks. For example, the wirelessspectrum may be used for both access links (e.g., links between basestations and user equipment (UEs)) and backhaul links (e.g., linksbetween base stations and the core network). In such integrated accessbackhaul (IAB) networks, the base station functionality can be logicallyseparated into a central unit (CU) and one or more distributed units(DUs). The CU hosts the radio resource control (RRC), service dataadaptation protocol (SDAP), and packet data convergence protocol (PDCP)layers that control the operation of one or more DUs. The DU hosts theradio link control (RLC), medium access control (MAC) and physical (PHY)layers. In an example IAB network architecture, the CU may beimplemented at an edge IAB node, while multiple DUs may be distributedthroughout the IAB network.

The CU in combination with one or more DUs, which may be co-locatedand/or distributed, may be referred to as a disaggregated base station.A disaggregated base station may be implemented within an IAB network orwithin other network configurations. The CU and DU(s) are connected viaan F1 interface, which utilizes an F1 application protocol (F1-AP) toconvey information between the CU and the DU(s). Enhancements to theF1-AP continue to be developed to support functionalities and featuresof disaggregated base stations.

BRIEF SUMMARY OF SOME EXAMPLES

The following presents a summary of one or more aspects of the presentdisclosure, in order to provide a basic understanding of such aspects.This summary is not an extensive overview of all contemplated featuresof the disclosure, and is intended neither to identify key or criticalelements of all aspects of the disclosure nor to delineate the scope ofany or all aspects of the disclosure. Its sole purpose is to presentsome concepts of one or more aspects of the disclosure in a form as aprelude to the more detailed description that is presented later.

In one example, a method of operation at a distributed unit (DU) of adisaggregated base station is disclosed. The method includes receiving ameasurement request from a central unit (CU) of the disaggregated basestation. The measurement request includes a measurement configurationassociated with at least one value to be obtained by the DU and areporting configuration for reporting the at least one value to the CU.The method further includes obtaining the at least one value inaccordance with the measurement configuration at the DU and sending ameasurement report associated with the at least one value from the DU tothe CU in accordance with the reporting configuration.

Another example provides a disaggregated base station within a wirelesscommunication network. The disaggregated base station includes atransceiver, a memory, and a processor communicatively coupled to thetransceiver and the memory. The processor and the memory can beconfigured to receive a measurement request from a central unit (CU) ofthe disaggregated base station at a distributed unit (DU) of thedisaggregated base station. The measurement request includes ameasurement configuration associated with at least one value to beobtained by the DU and a reporting configuration for reporting the atleast one value to the CU. The processor and the memory can further beconfigured to obtain the at least one value in accordance with themeasurement configuration at the DU and send a measurement reportassociated with the at least one value from the DU to the CU inaccordance with the reporting configuration.

Another example provides a disaggregated base station within a wirelesscommunication network. The disaggregated base station includes means forreceiving a measurement request from a central unit (CU) of thedisaggregated base station at a distributed unit (DU) of thedisaggregated base station. The measurement request includes ameasurement configuration associated with at least one value to beobtained by the DU and a reporting configuration for reporting the atleast one value to the CU. The disaggregated base station furtherincludes means for obtaining the at least one value in accordance withthe measurement configuration at the DU and means for sending ameasurement report associated with the at least one value from the DU tothe CU in accordance with the reporting configuration.

Another example provides a non-transitory computer-readable mediumhaving stored therein instructions executable by one or more processorsof a disaggregated base station to receive a measurement request from acentral unit (CU) of the disaggregated base station at a distributedunit (DU) of the disaggregated base station. The measurement requestincludes a measurement configuration associated with at least one valueto be obtained by the DU and a reporting configuration for reporting theat least one value to the CU. The non-transitory computer-readablemedium further includes instructions executable by one or moreprocessors of the disaggregated base station to obtain the at least onevalue in accordance with the measurement configuration at the DU andsend a measurement report associated with the at least one value fromthe DU to the CU in accordance with the reporting configuration.

In another example, a method of operation at a central unit (CU) of adisaggregated base station is disclosed. The method includes sending ameasurement request to a distributed unit (DU) of the disaggregated basestation. The measurement request includes a measurement configurationassociated with at least one value to be obtained by the DU and areporting configuration for reporting the at least one value to the CU.The method further includes receiving a measurement response from the DUconfirming configuration of the DU in accordance with the measurementconfiguration and the reporting configuration and receiving ameasurement report associated with the at least one value from the DU inaccordance with the reporting configuration.

Another example provides a disaggregated base station within a wirelesscommunication network. The disaggregated base station includes atransceiver, a memory, and a processor communicatively coupled to thetransceiver and the memory. The processor and the memory can beconfigured to, at a central unit (CU) of the disaggregated base station,sending a measurement request to a distributed unit (DU) of thedisaggregated base station. The measurement request includes ameasurement configuration associated with at least one value to beobtained by the DU and a reporting configuration for reporting the atleast one value to the CU. The processor and the memory can further beconfigured to receive a measurement response from the DU confirmingconfiguration of the DU in accordance with the measurement configurationand the reporting configuration and receive a measurement reportassociated with the at least one value from the DU in accordance withthe reporting configuration.

Another example provides a central unit (CU) of a disaggregated basestation within a wireless communication network. The CU of thedisaggregated base station includes means for sending a measurementrequest to a distributed unit (DU) of the disaggregated base station.The measurement request includes a measurement configuration associatedwith at least one value to be obtained by the DU and a reportingconfiguration for reporting the at least one value to the CU. The CU ofthe disaggregated base station further includes means for receiving ameasurement response from the DU confirming configuration of the DU inaccordance with the measurement configuration and the reportingconfiguration and means for receiving a measurement report associatedwith the at least one value from the DU in accordance with the reportingconfiguration.

Another example provides a non-transitory computer-readable mediumhaving stored therein instructions executable by one or more processorsof a central unit (CU) of a disaggregated base station to send ameasurement request to a distributed unit (DU) of the disaggregated basestation. The measurement request includes a measurement configurationassociated with at least one value to be obtained by the DU and areporting configuration for reporting the at least one value to the CU.The non-transitory computer-readable medium further includesinstructions executable by one or more processors of the CU of thedisaggregated base station to receive a measurement response from the DUconfirming configuration of the DU in accordance with the measurementconfiguration and the reporting configuration and receive a measurementreport associated with the at least one value from the DU in accordancewith the reporting configuration.

These and other aspects of the invention will become more fullyunderstood upon a review of the detailed description, which follows.Other aspects, features, and embodiments of the present invention willbecome apparent to those of ordinary skill in the art, upon reviewingthe following description of specific, exemplary embodiments of thepresent invention in conjunction with the accompanying figures. Whilefeatures of the present invention may be discussed relative to certainembodiments and figures below, all embodiments of the present inventioncan include one or more of the advantageous features discussed herein.In other words, while one or more embodiments may be discussed as havingcertain advantageous features, one or more of such features may also beused in accordance with the various embodiments of the inventiondiscussed herein. In similar fashion, while exemplary embodiments may bediscussed below as device, system, or method embodiments it should beunderstood that such exemplary embodiments can be implemented in variousdevices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a wireless communication systemaccording to some aspects.

FIG. 2 is a conceptual illustration of an example of a radio accessnetwork according to some aspects.

FIG. 3 is a schematic diagram illustrating organization of wirelessresources in an air interface utilizing orthogonal frequency divisionalmultiplexing (OFDM) according to some aspects.

FIG. 4 is a block diagram illustrating a wireless communication systemsupporting beamforming and/or multiple-input multiple-output (MIMO)communication according to some aspects.

FIG. 5 is a diagram illustrating an example of a contention based randomaccess procedure utilizing a random access channel (RACH) according tosome aspects.

FIG. 6 is a diagram illustrating an example of a non-contention basedrandom access procedure utilizing the RACH according to some aspects.

FIG. 7 is a diagram illustrating an example two-step RACH procedureaccording to some aspects.

FIG. 8 is a diagram illustrating an example of a radio protocolarchitecture for the user and control plane according to some aspects.

FIG. 9 is a diagram providing a high-level illustration of one exampleof a network configuration including an integrated access backhaul (IAB)network according to some aspects.

FIG. 10 is a diagram illustrating an example of IAB node functionalitywithin an IAB network according to some aspects.

FIG. 11 is a diagram illustrating an example of a disaggregated basestation according to some aspects.

FIG. 12 is a diagram illustrating exemplary signaling between a CU and aDU of a disaggregated base station to commence DU measurementconfiguration and reporting according to some aspects.

FIG. 13 is a diagram illustrating an example of a measurement requestfor configuring measurement and event reporting by a DU according tosome aspects.

FIG. 14 is a block diagram illustrating an example of a hardwareimplementation for an IAB node forming at least a part of adisaggregated base station employing a processing system according tosome aspects.

FIG. 15 is a flow chart illustrating an exemplary process for a CU toconfigure DU measurement and event reporting according to some aspects.

FIG. 16 is a flow chart illustrating an exemplary process for DUmeasurement and event reporting in accordance with a CU configurationaccording to some aspects.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the only configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purpose of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well known structures and components areshown in block diagram form in order to avoid obscuring such concepts.

The electromagnetic spectrum is often subdivided, based onfrequency/wavelength, into various classes, bands, channels, etc. In 5GNR two initial operating bands have been identified as frequency rangedesignations FR1 (410 MHz -7.125 GHz) and FR2 (24.25 GHz - 52.6 GHz). Itshould be understood that although a portion of FR1 is greater than 6GHz, FR1 is often referred to (interchangeably) as a “Sub-6 GHz” band invarious documents and articles. A similar nomenclature issue sometimesoccurs with regard to FR2, which is often referred to (interchangeably)as a “millimeter wave” band in documents and articles, despite beingdifferent from the extremely high frequency (EHF) band (30 GHz - 300GHz) which is identified by the International Telecommunications Union(ITU) as a “millimeter wave” band.

The frequencies between FR1 and FR2 are often referred to as mid-bandfrequencies. Recent 5G NR studies have identified an operating band forthese mid-band frequencies as frequency range designation FR3 (7.125GHz - 24.25 GHz). Frequency bands falling within FR3 may inherit FR1characteristics and/or FR2 characteristics, and thus may effectivelyextend features of FR1 and/or FR2 into mid-band frequencies. Inaddition, higher frequency bands are currently being explored to extend5G NR operation beyond 52.6 GHz. For example, three higher operatingbands have been identified as frequency range designations FR4-a orFR4-1 (52.6 GHz - 71 GHz), FR4 (52.6 GHz -114.25 GHz), and FR5 (114.25GHz - 300 GHz). Each of these higher frequency bands falls within theEHF band.

With the above aspects in mind, unless specifically stated otherwise, itshould be understood that the term “sub-6 GHz” or the like if usedherein may broadly represent frequencies that may be less than 6 GHz,may be within FR1, or may include mid-band frequencies. Further, unlessspecifically stated otherwise, it should be understood that the term“millimeter wave” or the like if used herein may broadly representfrequencies that may include mid-band frequencies, may be within FR2,FR4, FR4-a or FR4-1, and/or FR5, or may be within the EHF band.

While aspects and embodiments are described in this application byillustration to some examples, those skilled in the art will understandthat additional implementations and use cases may come about in manydifferent arrangements and scenarios. Innovations described herein maybe implemented across many differing platform types, devices, systems,shapes, sizes, and packaging arrangements. For example, embodimentsand/or uses may come about via integrated chip embodiments and othernon-module-component based devices (e.g., end-user devices, vehicles,communication devices, computing devices, industrial equipment,retail/purchasing devices, medical devices, AI-enabled devices, etc.).While some examples may or may not be specifically directed to use casesor applications, a wide assortment of applicability of describedinnovations may occur. Implementations may range a spectrum fromchip-level or modular components to non-modular, non-chip-levelimplementations and further to aggregate, distributed, or OEM devices orsystems incorporating one or more aspects of the described innovations.In some practical settings, devices incorporating described aspects andfeatures may also necessarily include additional components and featuresfor implementation and practice of claimed and described embodiments.For example, transmission and reception of wireless signals necessarilyincludes a number of components for analog and digital purposes (e.g.,hardware components including antenna, RF-chains, power amplifiers,modulators, buffer, processor(s), interleaver, adders/summers, etc.). Itis intended that innovations described herein may be practiced in a widevariety of devices, chip-level components, systems, distributedarrangements, end-user devices, etc. of varying sizes, shapes andconstitution.

Various aspects of the disclosure relate to measurement and eventreporting from a distributed unit (DU) of a disaggregated base stationto a central unit (CU) of the disaggregated base station. The CU canconfigure the DU with a measurement configuration associated with atleast one value to be obtained by the DU and a reporting configurationfor reporting the at least one value to the CU. The measurement reportscan be sent by the DU periodically or the measurement reports can beevent-triggered based on the reporting configuration. In addition, themeasurement reports can be UE-specific or DU/cell-specific. ForUE-specific measurement reports, the UE identifier (ID) may be includedin the measurement configuration and the measurement report.

The measurement configuration can include one or more of a parameterassociated with the at least one value, a measurement period for the atleast one value, or a filtering configuration for filtering the at leastone value. The reporting configuration can indicate the selectedparameter(s) associated with the at least one value to include in themeasurement report. In addition, for event-based reporting, thereporting configuration can further include one or more thresholdsassociated with the event. The threshold(s) may be used by the DU todetermine when to transmit the measurement report.

The values included in the measurement reports can include random accesschannel (RACH) report values, uplink measurements, radio link protocol(RLC) measurements, medium access control (MAC) protocol measurements,or other values associated with other types of measurements or events.For RACH reports, the parameter(s) may include at least one of a RACHindication, a timing advance, a detected power, a detected signalquality, a RACH trigger, a beam identifier, a synchronization signalblock (SSB) identifier, an uplink frequency band, a physical RACH(PRACH) resource, a RACH type, or a random access response (RAR) windowsize. In addition, for uplink measurements, the parameter(s) may includeat least one of a sounding reference signal (SRS) measurement, a phasetracking reference signal (PTRS) measurement, an angle of arrivalmeasurement, an interference over thermal (IoT) measurement, a hybridautomatic repeat request (HARQ) retransmission rate, a maximum number ofHARQ retransmissions reached indicator, or a beam measurement report.Furthermore, for RLC measurements, the parameter(s) may include at leastone of a downlink RLC buffer occupancy, a first average number of RLCretransmissions per data radio bearer, a second average number of RLCretransmissions per user equipment (UE), a third average number of RLCretransmissions per cell, or a maximum number of RLC retransmissionsdetected indicator. For MAC protocol measurements, the parameter(s) mayinclude at least a beam failure recovery statistic. Other types ofvalues may include, for example, the DU load, a remote interferencemeasurement detected indicator or a strong uplink interferencemeasurement detected indicator.

The various concepts presented throughout this disclosure may beimplemented across a broad variety of telecommunication systems, networkarchitectures, and communication standards. Referring now to FIG. 1 , asan illustrative example without limitation, various aspects of thepresent disclosure are illustrated with reference to a wirelesscommunication system 100. The wireless communication system 100 includesthree interacting domains: a core network 102, a radio access network(RAN) 104, and a user equipment (UE) 106. By virtue of the wirelesscommunication system 100, the UE 106 may be enabled to carry out datacommunication with an external data network 110, such as (but notlimited to) the Internet.

The RAN 104 may implement any suitable wireless communication technologyor technologies to provide radio access to the UE 106. As one example,the RAN 104 may operate according to 3rd Generation Partnership Project(3GPP) New Radio (NR) specifications, often referred to as 5G. Asanother example, the RAN 104 may operate under a hybrid of 5G NR andEvolved Universal Terrestrial Radio Access Network (eUTRAN) standards,often referred to as Long Term Evolution (LTE). The 3GPP refers to thishybrid RAN as a next-generation RAN, or NG-RAN. Of course, many otherexamples may be utilized within the scope of the present disclosure.

As illustrated, the RAN 104 includes a plurality of base stations 108.Broadly, a base station is a network element in a radio access networkresponsible for radio transmission and reception in one or more cells toor from a UE. In different technologies, standards, or contexts, a basestation may variously be referred to by those skilled in the art as abase transceiver station (BTS), a radio base station, a radiotransceiver, a transceiver function, a basic service set (BSS), anextended service set (ESS), an access point (AP), a Node B (NB), aneNode B (eNB), a gNode B (gNB), a transmission and reception point(TRP), or some other suitable terminology. In some examples, a basestation may include two or more TRPs that may be collocated ornon-collocated. Each TRP may communicate on the same or differentcarrier frequency within the same or different frequency band. Inexamples where the RAN 104 operates according to both the LTE and 5G NRstandards, one of the base stations may be an LTE base station, whileanother base station may be a 5G NR base station.

The RAN 104 is further illustrated supporting wireless communication formultiple mobile apparatuses. A mobile apparatus may be referred to asuser equipment (UE) in 3GPP standards, but may also be referred to bythose skilled in the art as a mobile station (MS), a subscriber station,a mobile unit, a subscriber unit, a wireless unit, a remote unit, amobile device, a wireless device, a wireless communications device, aremote device, a mobile subscriber station, an access terminal (AT), amobile terminal, a wireless terminal, a remote terminal, a handset, aterminal, a user agent, a mobile client, a client, or some othersuitable terminology. A UE may be an apparatus (e.g., a mobileapparatus) that provides a user with access to network services.

Within the present disclosure, a “mobile” apparatus need not necessarilyhave a capability to move and may be stationary. The term mobileapparatus or mobile device broadly refers to a diverse array of devicesand technologies. UEs may include a number of hardware structuralcomponents sized, shaped, and arranged to help in communication; suchcomponents can include antennas, antenna arrays, RF chains, amplifiers,one or more processors, etc. electrically coupled to each other. Forexample, some non-limiting examples of a mobile apparatus include amobile, a cellular (cell) phone, a smart phone, a session initiationprotocol (SIP) phone, a laptop, a personal computer (PC), a notebook, anetbook, a smartbook, a tablet, a personal digital assistant (PDA), anda broad array of embedded systems, e.g., corresponding to an “Internetof things” (IoT).

A mobile apparatus may additionally be an automotive or othertransportation vehicle, a remote sensor or actuator, a robot or roboticsdevice, a satellite radio, a global positioning system (GPS) device, anobject tracking device, a drone, a multi-copter, a quad-copter, a remotecontrol device, a consumer and/or wearable device, such as eyewear, awearable camera, a virtual reality device, a smart watch, a health orfitness tracker, a digital audio player (e.g., MP3 player), a camera, agame console, etc. A mobile apparatus may additionally be a digital homeor smart home device such as a home audio, video, and/or multimediadevice, an appliance, a vending machine, intelligent lighting, a homesecurity system, a smart meter, etc. A mobile apparatus may additionallybe a smart energy device, a security device, a solar panel or solararray, a municipal infrastructure device controlling electric power(e.g., a smart grid), lighting, water, etc., an industrial automationand enterprise device, a logistics controller, and/or agriculturalequipment, etc. Still further, a mobile apparatus may provide forconnected medicine or telemedicine support, e.g., health care at adistance. Telehealth devices may include telehealth monitoring devicesand telehealth administration devices, whose communication may be givenpreferential treatment or prioritized access over other types ofinformation, e.g., in terms of prioritized access for transport ofcritical service data, and/or relevant QoS for transport of criticalservice data.

Wireless communication between the RAN 104 and the UE 106 may bedescribed as utilizing an air interface. Transmissions over the airinterface from a base station (e.g., base station 108) to one or moreUEs (e.g., similar to UE 106) may be referred to as downlink (DL)transmission. In accordance with certain aspects of the presentdisclosure, the term downlink may refer to a point-to-multipointtransmission originating at a base station (e.g., base station 108).Another way to describe this scheme may be to use the term broadcastchannel multiplexing. Transmissions from a UE (e.g., UE 106) to a basestation (e.g., base station 108) may be referred to as uplink (UL)transmissions. In accordance with further aspects of the presentdisclosure, the term uplink may refer to a point-to-point transmissionoriginating at a UE (e.g., UE 106).

In some examples, access to the air interface may be scheduled, whereina scheduling entity (e.g., a base station 108) allocates resources forcommunication among some or all devices and equipment within its servicearea or cell. Within the present disclosure, as discussed further below,the scheduling entity may be responsible for scheduling, assigning,reconfiguring, and releasing resources for one or more scheduledentities (e.g., UEs 106). That is, for scheduled communication, aplurality of UEs 106, which may be scheduled entities, may utilizeresources allocated by the scheduling entity 108.

Base stations 108 are not the only entities that may function asscheduling entities. That is, in some examples, a UE may function as ascheduling entity, scheduling resources for one or more scheduledentities (e.g., one or more other UEs). For example, UEs may communicatedirectly with other UEs in a peer-to-peer or device-to-device fashionand/or in a relay configuration.

As illustrated in FIG. 1 , a scheduling entity 108 may broadcastdownlink traffic 112 to one or more scheduled entities (e.g., one ormore UEs 106). Broadly, the scheduling entity 108 is a node or deviceresponsible for scheduling traffic in a wireless communication network,including the downlink traffic 112 and, in some examples, uplink traffic116 from one or more scheduled entities (e.g., one or more UEs 106) tothe scheduling entity 108. On the other hand, the scheduled entity(e.g., a UE 106) is a node or device that receives downlink controlinformation 114, including but not limited to scheduling information(e.g., a grant), synchronization or timing information, or other controlinformation from another entity in the wireless communication networksuch as the scheduling entity 108.

In addition, the uplink and/or downlink control information and/ortraffic information may be transmitted on a waveform that may betime-divided into frames, subframes, slots, and/or symbols. As usedherein, a symbol may refer to a unit of time that, in an orthogonalfrequency division multiplexed (OFDM) waveform, carries one resourceelement (RE) per sub-carrier. A slot may carry 7 or 14 OFDM symbols. Asubframe may refer to a duration of 1 ms. Multiple subframes or slotsmay be grouped together to form a single frame or radio frame. Withinthe present disclosure, a frame may refer to a predetermined duration(e.g., 10 ms) for wireless transmissions, with each frame consisting of,for example, 10 subframes of 1 ms each. Of course, these definitions arenot required, and any suitable scheme for organizing waveforms may beutilized, and various time divisions of the waveform may have anysuitable duration.

In general, base stations 108 may include a backhaul interface forcommunication with a backhaul portion 120 of the wireless communicationsystem 100. The backhaul portion 120 may provide a link between a basestation 108 and the core network 102. Further, in some examples, abackhaul network may provide interconnection between the respective basestations 108. Various types of backhaul interfaces may be employed, suchas a direct physical connection, a virtual network, or the like usingany suitable transport network.

The core network 102 may be a part of the wireless communication system100 and may be independent of the radio access technology used in theRAN 104. In some examples, the core network 102 may be configuredaccording to 5G standards (e.g., 5GC). In other examples, the corenetwork 102 may be configured according to a 4G evolved packet core(EPC), or any other suitable standard or configuration.

Referring now to FIG. 2 , as an illustrative example without limitation,a schematic illustration of a radio access network (RAN) 200 accordingto some aspects of the present disclosure is provided. In some examples,the RAN 200 may be the same as the RAN 104 described above andillustrated in FIG. 1 .

The geographic region covered by the RAN 200 may be divided into anumber of cellular regions (cells) that can be uniquely identified by auser equipment (UE) based on an identification broadcasted over ageographical area from one access point or base station. FIG. 2illustrates cells 202, 204, 206, and 208, each of which may include oneor more sectors (not shown). A sector is a sub-area of a cell. Allsectors within one cell are served by the same base station. A radiolink within a sector can be identified by a single logicalidentification belonging to that sector. In a cell that is divided intosectors, the multiple sectors within a cell can be formed by groups ofantennas with each antenna responsible for communication with UEs in aportion of the cell.

Various base station arrangements can be utilized. For example, in FIG.2 , two base stations, base station 210 and base station 212 are shownin cells 202 and 204. A third base station, base station 214 is showncontrolling a remote radio head (RRH) 216 in cell 206. That is, a basestation can have an integrated antenna or can be connected to an antennaor RRH 216 by feeder cables. In the illustrated example, cells 202, 204,and 206 may be referred to as macrocells, as the base stations 210, 212,and 214 support cells having a large size. Further, a base station 218is shown in the cell 208, which may overlap with one or more macrocells.In this example, the cell 208 may be referred to as a small cell (e.g.,a microcell, picocell, femtocell, home base station, home Node B, homeeNode B, etc.), as the base station 218 supports a cell having arelatively small size. Cell sizing can be done according to systemdesign as well as component constraints.

It is to be understood that the RAN 200 may include any number ofwireless base stations and cells. Further, a relay node may be deployedto extend the size or coverage area of a given cell. The base stations210, 212, 214, 218 provide wireless access points to a core network forany number of mobile apparatuses. In some examples, the base stations210, 212, 214, and/or 218 may be the same as or similar to thescheduling entity 108 described above and illustrated in FIG. 1 .

FIG. 2 further includes an unmanned aerial vehicle (UAV) 220, which maybe a drone or quadcopter. The UAV 220 may be configured to function as abase station, or more specifically as a mobile base station. That is, insome examples, a cell may not necessarily be stationary, and thegeographic area of the cell may move according to the location of amobile base station, such as the UAV 220.

Within the RAN 200, the cells may include UEs that may be incommunication with one or more sectors of each cell. Further, each basestation 210, 212, 214, 218, and 220 may be configured to provide anaccess point to a core network 102 (see FIG. 1 ) for all the UEs in therespective cells. For example, UEs 222 and 224 may be in communicationwith base station 210; UEs 226 and 228 may be in communication with basestation 212; UEs 230 and 232 may be in communication with base station214 by way of RRH 216; UE 234 may be in communication with base station218; and UE 236 may be in communication with mobile base station 220. Insome examples, the UEs 222, 224, 226, 228, 230, 232, 234, 236, 238, 240,and/or 242 may be the same as or similar to the UE/scheduled entity 106described above and illustrated in FIG. 1 . In some examples, the UAV220 (e.g., the quadcopter) can be a mobile network node and may beconfigured to function as a UE. For example, the UAV 220 may operatewithin cell 202 by communicating with base station 210.

In a further aspect of the RAN 200, sidelink signals may be used betweenUEs without necessarily relying on scheduling or control informationfrom a base station. Sidelink communication may be utilized, forexample, in a device-to-device (D2D) network, peer-to-peer (P2P)network, vehicle-to-vehicle (V2V) network, vehicle-to-everything (V2X)network, and/or other suitable sidelink network. For example, two ormore UEs (e.g., UEs 238, 240, and 242) may communicate with each otherusing sidelink signals 237 without relaying that communication through abase station. In some examples, the UEs 238, 240, and 242 may eachfunction as a scheduling entity or transmitting sidelink device and/or ascheduled entity or a receiving sidelink device to schedule resourcesand communicate sidelink signals 237 therebetween without relying onscheduling or control information from a base station. In otherexamples, two or more UEs (e.g., UEs 226 and 228) within the coveragearea of a base station (e.g., base station 212) may also communicatesidelink signals 227 over a direct link (sidelink) without conveyingthat communication through the base station 212. In this example, thebase station 212 may allocate resources to the UEs 226 and 228 for thesidelink communication.

In order for transmissions over the air interface to obtain a low blockerror rate (BLER) while still achieving very high data rates, channelcoding may be used. That is, wireless communication may generallyutilize a suitable error correcting block code. In a typical block code,an information message or sequence is split up into code blocks (CBs),and an encoder (e.g., a CODEC) at the transmitting device thenmathematically adds redundancy to the information message. Exploitationof this redundancy in the encoded information message can improve thereliability of the message, enabling correction for any bit errors thatmay occur due to the noise.

Data coding may be implemented in multiple manners. In early 5G NRspecifications, user data is coded using quasi-cyclic low-density paritycheck (LDPC) with two different base graphs: one base graph is used forlarge code blocks and/or high code rates, while the other base graph isused otherwise. Control information and the physical broadcast channel(PBCH) are coded using Polar coding, based on nested sequences. Forthese channels, puncturing, shortening, and repetition are used for ratematching.

Aspects of the present disclosure may be implemented utilizing anysuitable channel code. Various implementations of base stations and UEsmay include suitable hardware and capabilities (e.g., an encoder, adecoder, and/or a CODEC) to utilize one or more of these channel codesfor wireless communication.

In the RAN 200, the ability of UEs to communicate while moving,independent of their location, is referred to as mobility. The variousphysical channels between the UE and the RAN 200 are generally set up,maintained, and released under the control of an access and mobilitymanagement function (AMF). In some scenarios, the AMF may include asecurity context management function (SCMF) and a security anchorfunction (SEAF) that performs authentication. The SCMF can manage, inwhole or in part, the security context for both the control plane andthe user plane functionality.

In various aspects of the disclosure, the RAN 200 may utilize DL-basedmobility or UL-based mobility to enable mobility and handovers (i.e.,the transfer of a UE’s connection from one radio channel to another). Ina network configured for DL-based mobility, during a call with ascheduling entity, or at any other time, a UE may monitor variousparameters of the signal from its serving cell as well as variousparameters of neighboring cells. Depending on the quality of theseparameters, the UE may maintain communication with one or more of theneighboring cells. During this time, if the UE moves from one cell toanother, or if signal quality from a neighboring cell exceeds that fromthe serving cell for a given amount of time, the UE may undertake ahandoff or handover from the serving cell to the neighboring (target)cell. For example, the UE 224 may move from the geographic areacorresponding to its serving cell 202 to the geographic areacorresponding to a neighbor cell 206. When the signal strength orquality from the neighbor cell 206 exceeds that of its serving cell 202for a given amount of time, the UE 224 may transmit a reporting messageto its serving base station 210 indicating this condition. In response,the UE 224 may receive a handover command, and the UE may undergo ahandover to the cell 206.

In a network configured for UL-based mobility, UL reference signals fromeach UE may be utilized by the network to select a serving cell for eachUE. In some examples, the base stations 210, 212, and 214/216 maybroadcast unified synchronization signals (e.g., unified PrimarySynchronization Signals (PSSs), unified Secondary SynchronizationSignals (SSSs) and unified Physical Broadcast Channels (PBCHs)). The UEs222, 224, 226, 228, 230, and 232 may receive the unified synchronizationsignals, derive the carrier frequency, and slot timing from thesynchronization signals, and in response to deriving timing, transmit anuplink pilot or reference signal. The uplink pilot signal transmitted bya UE (e.g., UE 224) may be concurrently received by two or more cells(e.g., base stations 210 and 214/216) within the RAN 200. Each of thecells may measure a strength of the pilot signal, and the radio accessnetwork (e.g., one or more of the base stations 210 and 214/216 and/or acentral node within the core network) may determine a serving cell forthe UE 224. As the UE 224 moves through the RAN 200, the RAN 200 maycontinue to monitor the uplink pilot signal transmitted by the UE 224.When the signal strength or quality of the pilot signal measured by aneighboring cell exceeds that of the signal strength or quality measuredby the serving cell, the RAN 200 may handover the UE 224 from theserving cell to the neighboring cell, with or without informing the UE224.

Although the synchronization signal transmitted by the base stations210, 212, and 214/216 may be unified, the synchronization signal may notidentify a particular cell, but rather may identify a zone of multiplecells operating on the same frequency and/or with the same timing. Theuse of zones in 5G networks or other next generation communicationnetworks enables the uplink-based mobility framework and improves theefficiency of both the UE and the network, since the number of mobilitymessages that need to be exchanged between the UE and the network may bereduced.

In various implementations, the air interface in the radio accessnetwork 200 may utilize licensed spectrum, unlicensed spectrum, orshared spectrum. Licensed spectrum provides for exclusive use of aportion of the spectrum, generally by virtue of a mobile networkoperator purchasing a license from a government regulatory body.Unlicensed spectrum provides for shared use of a portion of the spectrumwithout need for a government-granted license. While compliance withsome technical rules is generally still required to access unlicensedspectrum, generally, any operator or device may gain access. Sharedspectrum may fall between licensed and unlicensed spectrum, whereintechnical rules or limitations may be required to access the spectrum,but the spectrum may still be shared by multiple operators and/ormultiple RATs. For example, the holder of a license for a portion oflicensed spectrum may provide licensed shared access (LSA) to share thatspectrum with other parties, e.g., with suitable licensee-determinedconditions to gain access.

Devices communicating in the radio access network 200 may utilize one ormore multiplexing techniques and multiple access algorithms to enablesimultaneous communication of the various devices. For example, 5G NRspecifications provide multiple access for UL transmissions from UEs 222and 224 to base station 210, and for multiplexing for DL transmissionsfrom base station 210 to one or more UEs 222 and 224, utilizingorthogonal frequency division multiplexing (OFDM) with a cyclic prefix(CP). In addition, for UL transmissions, 5G NR specifications providesupport for discrete Fourier transform-spread-OFDM (DFT-s-OFDM) with aCP (also referred to as single-carrier FDMA (SC-FDMA)). However, withinthe scope of the present disclosure, multiplexing and multiple accessare not limited to the above schemes, and may be provided utilizing timedivision multiple access (TDMA), code division multiple access (CDMA),frequency division multiple access (FDMA), sparse code multiple access(SCMA), resource spread multiple access (RSMA), or other suitablemultiple access schemes. Further, multiplexing DL transmissions from thebase station 210 to UEs 222 and 224 may be provided utilizing timedivision multiplexing (TDM), code division multiplexing (CDM), frequencydivision multiplexing (FDM), orthogonal frequency division multiplexing(OFDM), sparse code multiplexing (SCM), or other suitable multiplexingschemes.

Devices in the radio access network 200 may also utilize one or moreduplexing algorithms. Duplex refers to a point-to-point communicationlink where both endpoints can communicate with one another in bothdirections. Full-duplex means both endpoints can simultaneouslycommunicate with one another. Half-duplex means only one endpoint cansend information to the other at a time. Half-duplex emulation isfrequently implemented for wireless links utilizing time division duplex(TDD). In TDD, transmissions in different directions on a given channelare separated from one another using time division multiplexing. Thatis, in some scenarios, a channel is dedicated for transmissions in onedirection, while at other times the channel is dedicated fortransmissions in the other direction, where the direction may changevery rapidly, e.g., several times per slot. In a wireless link, afull-duplex channel generally relies on physical isolation of atransmitter and receiver, and suitable interference cancellationtechnologies. Full-duplex emulation is frequently implemented forwireless links by utilizing frequency division duplex (FDD) or spatialdivision duplex (SDD). In FDD, transmissions in different directions mayoperate at different carrier frequencies (e.g., within paired spectrum).In SDD, transmissions in different directions on a given channel areseparated from one another using spatial division multiplexing (SDM). Inother examples, full-duplex communication may be implemented withinunpaired spectrum (e.g., within a single carrier bandwidth), wheretransmissions in different directions occur within different sub-bandsof the carrier bandwidth. This type of full-duplex communication may bereferred to herein as sub-band full duplex (SBFD), also known asflexible duplex.

Various aspects of the present disclosure will be described withreference to an OFDM waveform, schematically illustrated in FIG. 3 . Itshould be understood by those of ordinary skill in the art that thevarious aspects of the present disclosure may be applied to an SC-FDMAwaveform in substantially the same way as described herein below. Thatis, while some examples of the present disclosure may focus on an OFDMlink for clarity, it should be understood that the same principles maybe applied as well to SC-FDMA waveforms.

Referring now to FIG. 3 , an expanded view of an exemplary subframe 302is illustrated, showing an OFDM resource grid. However, as those skilledin the art will readily appreciate, the PHY transmission structure forany particular application may vary from the example described here,depending on any number of factors. Here, time is in the horizontaldirection with units of OFDM symbols; and frequency is in the verticaldirection with units of subcarriers of the carrier.

The resource grid 304 may be used to schematically representtime-frequency resources for a given antenna port. That is, in amultiple-input-multiple-output (MIMO) implementation with multipleantenna ports available, a corresponding multiple number of resourcegrids 304 may be available for communication. The resource grid 304 isdivided into multiple resource elements (REs) 306. An RE, which is 1subcarrier × 1 symbol, is the smallest discrete part of thetime-frequency grid, and contains a single complex value representingdata from a physical channel or signal. Depending on the modulationutilized in a particular implementation, each RE may represent one ormore bits of information. In some examples, a block of REs may bereferred to as a physical resource block (PRB) or more simply a resourceblock (RB) 308, which contains any suitable number of consecutivesubcarriers in the frequency domain. In one example, an RB may include12 subcarriers, a number independent of the numerology used. In someexamples, depending on the numerology, an RB may include any suitablenumber of consecutive OFDM symbols in the time domain. Within thepresent disclosure, it is assumed that a single RB such as the RB 308entirely corresponds to a single direction of communication (eithertransmission or reception for a given device).

A set of continuous or discontinuous resource blocks may be referred toherein as a Resource Block Group (RBG), sub-band, or bandwidth part(BWP). A set of sub-bands or BWPs may span the entire bandwidth.Scheduling of scheduled entities (e.g., UEs) for downlink, uplink, orsidelink transmissions typically involves scheduling one or moreresource elements 306 within one or more sub-bands or bandwidth parts(BWPs). Thus, a UE generally utilizes only a subset of the resource grid304. In some examples, an RB may be the smallest unit of resources thatcan be allocated to a UE. Thus, the more RBs scheduled for a UE, and thehigher the modulation scheme chosen for the air interface, the higherthe data rate for the UE. The RBs may be scheduled by a schedulingentity, such as a base station (e.g., gNB, eNB, etc.), or may beself-scheduled by a UE implementing D2D sidelink communication.

In this illustration, the RB 308 is shown as occupying less than theentire bandwidth of the subframe 302, with some subcarriers illustratedabove and below the RB 308. In a given implementation, the subframe 302may have a bandwidth corresponding to any number of one or more RBs 308.Further, in this illustration, the RB 308 is shown as occupying lessthan the entire duration of the subframe 302, although this is merelyone possible example.

Each 1 ms subframe 302 may consist of one or multiple adjacent slots. Inthe example shown in FIG. 3 , one subframe 302 includes four slots 310,as an illustrative example. In some examples, a slot may be definedaccording to a specified number of OFDM symbols with a given cyclicprefix (CP) length. For example, a slot may include 7 or 14 OFDM symbolswith a nominal CP. Additional examples may include mini-slots, sometimesreferred to as shortened transmission time intervals (TTIs), having ashorter duration (e.g., one to three OFDM symbols). These mini-slots orshortened transmission time intervals (TTIs) may in some cases betransmitted occupying resources scheduled for ongoing slot transmissionsfor the same or for different UEs. Any number of resource blocks may beutilized within a subframe or slot.

An expanded view of one of the slots 310 illustrates the slot 310including a control region 312 and a data region 314. In general, thecontrol region 312 may carry control channels, and the data region 314may carry data channels. Of course, a slot may contain all DL, all UL,or at least one DL portion and at least one UL portion. The structureillustrated in FIG. 3 is merely exemplary in nature, and different slotstructures may be utilized, and may include one or more of each of thecontrol region(s) and data region(s).

Although not illustrated in FIG. 3 , the various REs 306 within a RB 308may be scheduled to carry one or more physical channels, includingcontrol channels, shared channels, data channels, etc. Other REs 306within the RB 308 may also carry pilots or reference signals. Thesepilots or reference signals may provide for a receiving device toperform channel estimation of the corresponding channel, which mayenable coherent demodulation/detection of the control and/or datachannels within the RB 308.

In some examples, the slot 310 may be utilized for broadcast, multicast,groupcast, or unicast communication. For example, a broadcast,multicast, or groupcast communication may refer to a point-to-multipointtransmission by one device (e.g., a base station, UE, or other similardevice) to other devices. Here, a broadcast communication is deliveredto all devices, whereas a multicast or groupcast communication isdelivered to multiple intended recipient devices. A unicastcommunication may refer to a point-to-point transmission by a one deviceto a single other device.

In an example of cellular communication over a cellular carrier via a Uuinterface, for a DL transmission, the scheduling entity (e.g., a basestation) may allocate one or more REs 306 (e.g., within the controlregion 312) to carry DL control information including one or more DLcontrol channels, such as a physical downlink control channel (PDCCH),to one or more scheduled entities (e.g., UEs). The PDCCH carriesdownlink control information (DCI) including but not limited to powercontrol commands (e.g., one or more open loop power control parametersand/or one or more closed loop power control parameters), schedulinginformation, a grant, and/or an assignment of REs for DL and ULtransmissions. The PDCCH may further carry HARQ feedback transmissionssuch as an acknowledgment (ACK) or negative acknowledgment (NACK). HARQis a technique well-known to those of ordinary skill in the art, whereinthe integrity of packet transmissions may be checked at the receivingside for accuracy, e.g., utilizing any suitable integrity checkingmechanism, such as a checksum or a cyclic redundancy check (CRC). If theintegrity of the transmission is confirmed, an ACK may be transmitted,whereas if not confirmed, a NACK may be transmitted. In response to aNACK, the transmitting device may send a HARQ retransmission, which mayimplement chase combining, incremental redundancy, etc.

The base station may further allocate one or more REs 306 (e.g., in thecontrol region 312 or the data region 314) to carry other DL signals,such as a demodulation reference signal (DMRS); a phase-trackingreference signal (PT-RS); a channel state information (CSI) referencesignal (CSI-RS); and a synchronization signal block (SSB). SSBs may bebroadcast at regular intervals based on a periodicity (e.g., 5, 10, 20,30, 80, or 130 ms). An SSB includes a primary synchronization signal(PSS), a secondary synchronization signal (SSS), and a physicalbroadcast control channel (PBCH). A UE may utilize the PSS and SSS toachieve radio frame, subframe, slot, and symbol synchronization in thetime domain, identify the center of the channel (system) bandwidth inthe frequency domain, and identify the physical cell identity (PCI) ofthe cell.

The PBCH in the SSB may further include a master information block (MIB)that includes various system information, along with parameters fordecoding a system information block (SIB). The SIB may be, for example,a SystemInformationType 1 (SIB1) that may include various additionalsystem information. The MIB and SIB1 together provide the minimum systeminformation (SI) for initial access. Examples of system informationtransmitted in the MIB may include, but are not limited to, a subcarrierspacing (e.g., default downlink numerology), system frame number, aconfiguration of a PDCCH control resource set (CORESET) (e.g., PDCCHCORESET0), a cell barred indicator, a cell reselection indicator, araster offset, and a search space for SIB1. Examples of remainingminimum system information (RMSI) transmitted in the SIB 1 may include,but are not limited to, a random access search space, a paging searchspace, downlink configuration information, and uplink configurationinformation. A base station may transmit other system information (OSI)as well.

In an UL transmission, the scheduled entity (e.g., UE) may utilize oneor more REs 306 to carry UL control information (UCI) including one ormore UL control channels, such as a physical uplink control channel(PUCCH), to the scheduling entity. UCI may include a variety of packettypes and categories, including pilots, reference signals, andinformation configured to enable or assist in decoding uplink datatransmissions. Examples of uplink reference signals may include asounding reference signal (SRS) and an uplink DMRS. In some examples,the UCI may include a scheduling request (SR), i.e., request for thescheduling entity to schedule uplink transmissions. Here, in response tothe SR transmitted on the UCI, the scheduling entity may transmitdownlink control information (DCI) that may schedule resources foruplink packet transmissions. UCI may also include HARQ feedback, channelstate feedback (CSF), such as a CSI report, or any other suitable UCI.

In addition to control information, one or more REs 306 (e.g., withinthe data region 314) may be allocated for data traffic. Such datatraffic may be carried on one or more traffic channels, such as, for aDL transmission, a physical downlink shared channel (PDSCH); or for anUL transmission, a physical uplink shared channel (PUSCH). In someexamples, one or more REs 306 within the data region 314 may beconfigured to carry other signals, such as one or more SIBs and DMRSs.

In an example of sidelink communication over a sidelink carrier via aproximity service (ProSe) PC5 interface, the control region 312 of theslot 310 may include a physical sidelink control channel (PSCCH)including sidelink control information (SCI) transmitted by aninitiating (transmitting) sidelink device (e.g., Tx V2X device or otherTx UE) towards a set of one or more other receiving sidelink devices(e.g., Rx V2X device or other Rx UE). The data region 314 of the slot310 may include a physical sidelink shared channel (PSSCH) includingsidelink data traffic transmitted by the initiating (transmitting)sidelink device within resources reserved over the sidelink carrier bythe transmitting sidelink device via the SCI. Other information mayfurther be transmitted over various REs 306 within slot 310. Forexample, HARQ feedback information may be transmitted in a physicalsidelink feedback channel (PSFCH) within the slot 310 from the receivingsidelink device to the transmitting sidelink device. In addition, one ormore reference signals, such as a sidelink SSB, a sidelink CSI-RS, asidelink SRS, and/or a sidelink positioning reference signal (PRS) maybe transmitted within the slot 310.

These physical channels described above are generally multiplexed andmapped to transport channels for handling at the medium access control(MAC) layer. Transport channels carry blocks of information calledtransport blocks (TB). The transport block size (TBS), which maycorrespond to a number of bits of information, may be a controlledparameter, based on the modulation and coding scheme (MCS) and thenumber of RBs in a given transmission.

The channels or carriers illustrated in FIG. 3 are not necessarily allof the channels or carriers that may be utilized between devices, andthose of ordinary skill in the art will recognize that other channels orcarriers may be utilized in addition to those illustrated, such as othertraffic, control, and feedback channels.

In some aspects of the disclosure, the scheduling entity and/orscheduled entity may be configured for beamforming and/or multiple-inputmultiple-output (MIMO) technology. FIG. 4 illustrates an example of awireless communication system supporting beamforming and/or MIMO. In aMIMO system, a transmitter 402 includes multiple transmit antennas 404(e.g., N transmit antennas) and a receiver 406 includes multiple receiveantennas 408 (e.g., M receive antennas). Thus, there are N × M signalpaths 410 from the transmit antennas 404 to the receive antennas 408.Each of the transmitter 402 and the receiver 406 may be implemented, forexample, within a scheduling entity, a scheduled entity, or any othersuitable wireless communication device.

The use of such multiple antenna technology enables the wirelesscommunication system to exploit the spatial domain to support spatialmultiplexing, beamforming, and transmit diversity. Spatial multiplexingmay be used to transmit different streams of data, also referred to aslayers, simultaneously on the same time-frequency resource. The datastreams may be transmitted to a single UE to increase the data rate orto multiple UEs to increase the overall system capacity, the latterbeing referred to as multi-user MIMO (MU-MIMO). This is achieved byspatially precoding each data stream (i.e., multiplying the data streamswith different weighting and phase shifting) and then transmitting eachspatially precoded stream through multiple transmit antennas on thedownlink. The spatially precoded data streams arrive at the UE(s) withdifferent spatial signatures, which enables each of the UE(s) to recoverthe one or more data streams destined for that UE. On the uplink, eachUE transmits a spatially precoded data stream, which enables the basestation to identify the source of each spatially precoded data stream.

The number of data streams or layers corresponds to the rank of thetransmission. In general, the rank of the MIMO system is limited by thenumber of transmit or receive antennas 404 or 408, whichever is lower.In addition, the channel conditions at the UE, as well as otherconsiderations, such as the available resources at the base station, mayalso affect the transmission rank. For example, the rank (and therefore,the number of data streams) assigned to a particular UE on the downlinkmay be determined based on the rank indicator (RI) transmitted from theUE to the base station. The RI may be determined based on the antennaconfiguration (e.g., the number of transmit and receive antennas) and ameasured signal-to-interference-and-noise ratio (SINR) on each of thereceive antennas. The RI may indicate, for example, the number of layersthat may be supported under the current channel conditions. The basestation may use the RI, along with resource information (e.g., theavailable resources and amount of data to be scheduled for the UE), toassign a transmission rank to the UE.

In one example, as shown in FIG. 4 , a rank-2 spatial multiplexingtransmission on a 2×2 MIMO antenna configuration will transmit one datastream from each transmit antenna 404. Each data stream reaches eachreceive antenna 408 along a different signal path 410. The receiver 406may then reconstruct the data streams using the received signals fromeach receive antenna 408.

Beamforming is a signal processing technique that may be used at thetransmitter 402 or receiver 406 to shape or steer an antenna beam (e.g.,a transmit beam or receive beam) along a spatial path between thetransmitter 402 and the receiver 406. Beamforming may be achieved bycombining the signals communicated via antennas 404 or 408 (e.g.,antenna elements of an antenna array module) such that some of thesignals experience constructive interference while others experiencedestructive interference. To create the desired constructive/destructiveinterference, the transmitter 402 or receiver 406 may apply amplitudeand/or phase offsets to signals transmitted or received from each of theantennas 404 or 408 associated with the transmitter 402 or receiver 406.

In some examples, to select a particular beam for communication with aUE, the base station may transmit a reference signal, such as an SSB orchannel state information reference signal (CSI-RS), on each of aplurality of beams (SSB beams) in a beam-sweeping manner. The UE maymeasure the reference signal received power (RSRP), reference signalreceived quality (RSRQ) or SINR on each of the beams and transmit a beammeasurement report to the base station indicating the RSRP of each ofthe measured beams. The base station may then select the particular beamfor communication with the UE based on the beam measurement report. Inother examples, when the channel is reciprocal, the base station mayderive the particular beam to communicate with the UE based on uplinkmeasurements of one or more uplink reference signals, such as a soundingreference signal (SRS).

In order to gain access to a cell, a UE may perform a random accessprocedure over a physical random access channel (PRACH). The UE mayidentify a random access search space including PRACH resources forinitiating a RACH procedure from the SIB 1. For example, a random accessprocess may be commenced after a UE acquires a cell and determinesoccurrence of a RACH occasion (e.g., PRACH resources) after reading SSBand a SIB 1. The SSB provides the initial system information (SI), andthe SIB 1 (and other SIB blocks) provide the remaining minimum SI(RMSI). For example, the PBCH MIB of the SSB may carry a first part ofthe SI that a user equipment (UE) needs in order to access a network.The SIBs (e.g., SIB1 and SIB2) can carry the RMSI that a UE needs togain access to the network.

RACH procedures may be performed in various scenarios, such as loss ofuplink synchronization, lack of available PUCCH resources, schedulingrequest failure, and other use cases. In addition, a RACH procedure maybe contention-based or contention-free and may include a 2-step RACHprocess (contention-based or contention-free), a 3-step RACH process(contention-free), or a 4-step RACH process (contention-based).

FIG. 5 is a diagram illustrating an example of a 4-step contention-basedrandom access (CBRA) procedure 500 between a base station 502 and a UE504. The base station 502 may correspond, for example, to any of thescheduling entities shown in FIGS. 1 and/or 2 . In addition, the UE 504may correspond, for example, to any of the scheduled entities shown inFIGS. 1 and/or 2 .

The random access procedure 500 shown in FIG. 5 is initiated by the UE504 randomly selecting a preamble from an available set of preambleswithin the cell served by the base station 502, and transmitting theselected preamble to the base station 502 in a RACH preamble message 506(msg1). In an example, the UE 504 may select from 64 possible preamblesequences for inclusion in the RACH preamble message 506. The msg 1 506may be transmitted by the UE 504 over a selected PRACH resource withpower ramping. The selected PRACH resource may include supplementaryuplink resources or normal uplink resources. Here, supplementary uplinkresources include lower frequency resources than normal uplinkresources. Thus, supplementary uplink resources and uplink resourceseach correspond to a different respective uplink frequency band. Themsg1 506 may further be communicated on a beam selected by the UE 504based on beam measurements (e.g., RSRP/RSRQ/SINR) performed by the UE504. The beam may correspond, for example, to an SSB beam.

If the preamble is successfully detected by the base station 502, thebase station 502 transmits a random access response (RAR) message 508(msg2) including a PDCCH and PDSCH to the UE 504. If no msg2 (RAR) 508is received within a RAR window, the UE 504 may retransmit msg1 506 withpower boost. The msg2 508 (PDCCH + PDSCH) includes an identifier of thepreamble sent by the UE 504, a Timing Advance (TA), a temporary cellradio network temporary identifier (TC-RNTI) or random access (RA) RNTIfor the UE 504 and a grant of assigned uplink (UL) resources. The PDCCHin msg2 508 may be scrambled with the RA-RNTI, which is a function of aRACH occasion (RO) (e.g., time-frequency resources allocated for RACHmsg1) that the UE 504 used to send msg1 506. A medium access control -control element (MAC-CE) within the PDSCH provides an acknowledgement ofthe reception of msg1 and the UL grant. To receive msg2 508, the UE 504may monitor DCI 1_0 for the PDCCH scrambled with the RA-RNTIcorresponding to the RO used by the UE 504 to transmit msg1 506, and ifdetected, proceeds with PDSCH decoding. Upon receipt of the RAR message508, the UE 504 compares the preamble ID to the preamble sent by thescheduled entity in the RACH preamble message 506. If the preamble IDmatches the preamble sent in the RACH preamble message 506, the UE 504applies the timing advance and starts a contention resolution procedure.

Since the preamble is selected randomly by the scheduled entity, ifanother scheduled entity selects the same preamble in the same RO, acollision may result between the two scheduled entities. Any collisionsmay then be resolved using the contention resolution procedure. Duringcontention resolution, the UE 504 transmits an uplink message (msg3) 510on the common control channel (CCCH) using the TA and assigned uplinkresources in the PDSCH of msg2 508. In an example, the uplink message510 is a Layer 2/Layer 3 (L2/L3) message, such as a Radio ResourceControl (RRC) Connection Request message. The uplink message 510includes an identifier of the UE 504 (UE-ID) for use by the schedulingentity in resolving any collisions. Although other scheduled entitiesmay transmit colliding uplink messages utilizing the TA and assigneduplink resources, these colliding uplink messages will likely not besuccessfully decoded at the scheduling entity since the colliding uplinkmessages were transmitted with TAs that were not intended for thosescheduled entities.

Upon successfully decoding the uplink message, the base station 502transmits a contention resolution message 512 to the UE 504 (msg4). Thecontention resolution message 512 may be, for example, an RRC-ConnectionSetup message. In addition, the contention resolution message 512includes the identifier of the UE 504 that was received in the uplinkmessage 510. The UE 504, upon receiving its own identity back in thecontention resolution message 512, concludes that the random accessprocedure was successful and completes the RRC connection setup process.Any other scheduled entity receiving the RRC-Connection Setup messagewith the identity of the UE 504 will conclude that the random accessprocedure failed and re-initialize the random access procedure.

FIG. 6 is a diagram illustrating an example of a contention-free randomaccess (CFRA) procedure 600 between a base station 602 and a UE 604. Thebase station 602 may correspond, for example, to any of the schedulingentities shown in FIGS. 1 and/or 2 . In addition, the UE 604 maycorrespond, for example, to any of the scheduled entities shown in FIGS.1 and/or 2 .

The CFRA procedure 600 may be used, for example, during handovers, afteruplink synchronization loss or positioning of the scheduled entity. TheCFRA procedure is initiated by the base station 602 selecting a preamblefrom a reserved set of preambles within the cell served by the basestation 602, and transmitting the selected preamble to the UE 604 in aRACH preamble assignment message 606. In an example, the reserved set ofpreambles may be separate from the pool of preambles available forrandom selection in contention based random access. Thus, the reservedset of preambles may be assigned by the scheduling entity in acontention-free manner to avoid PRACH collisions.

The UE 604 may then transmit the assigned preamble to the base station602 in a RACH preamble message 608 on a selected PRACH resource withinSUL or normal UL resources and selected beam. The base station 602 maythen transmit a random access response (RAR) message 610 on the physicaldownlink control channel (PDCCH). The RAR message 610 includes anidentifier of the preamble sent by the UE 604, a Timing Advance (TA), atemporary cell radio network temporary identifier (TC-RNTI) or randomaccess (RA) RNTI for the UE 604 and a grant of assigned uplinkresources. Upon receipt of the RAR message 610, the UE 604 applies thetiming advance and may initiate an uplink transmission 612 using theassigned uplink resources.

The four-step CBRA procedure 500 or the three-step CFRA procedure 600can be compressed into the two-step random-access procedure 700illustrated in FIG. 7 . The two-step random-access procedure 700 reducesoverhead and latency associated with control signaling by removing atransmission in each direction between the UE 704 and base station orscheduling entity, such as the illustrated gNB 702. In comparison toFIG. 5 , the two-step random-access procedure 700 commences with atransmission by the UE 704 of a single message (msgA 706) that includesthe RACH preamble message 506 and uplink message 510 sent of thecontention-based random-access procedure 500. Here, the uplink message510 may be a scheduled PUSCH transmission sent over a PUSCH resource andthe RACH preamble message 506 may be sent over a selected PRACHresource. The gNB 702 responds with a single message (msgB 708) thatincludes the random-access response 508 and the contention resolutionmessage 512.

The radio protocol architecture for a radio access network, such as theradio access network 104 shown in FIG. 1 and/or the radio access network200 shown in FIG. 2 , may take on various forms depending on theparticular application. An example of a radio protocol architecture forthe user and control planes is illustrated FIG. 8 .

As illustrated in FIG. 8 , the radio protocol architecture for the UEand the base station includes three layers: layer 1 (L1), layer 2 (L2),and layer 3 (L3). L1 is the lowest layer and implements various physicallayer signal processing functions. L1 will be referred to herein as thephysical layer 806. L2 808 is above the physical layer 806 and isresponsible for the link between the UE and base station over thephysical layer 806.

In the user plane, the L2 layer 808 includes a media access control(MAC) layer 810, a radio link control (RLC) layer 812, a packet dataconvergence protocol (PDCP) 814 layer, and a service data adaptationprotocol (SDAP) layer 816, which are terminated at the base station onthe network side. Although not shown, the UE may have several upperlayers above the L2 layer 808 including at least one network layer(e.g., IP layer and user data protocol (UDP) layer) that is terminatedat the User Plane Function (UPF) on the network side and one or moreapplication layers.

The SDAP layer 816 provides a mapping between a 5G core (5GC) quality ofservice (QoS) flow and a data radio bearer and performs QoS flow IDmarking in both downlink and uplink packets. The PDCP layer 814 providespacket sequence numbering, in-order delivery of packets, retransmissionof PDCP protocol data units (PDUs), and transfer of upper layer datapackets to lower layers. PDU’s may include, for example, InternetProtocol (IP) packets, Ethernet frames and other unstructured data(i.e., Machine-Type Communication (MTC), hereinafter collectivelyreferred to as “packets”). The PDCP layer 814 also provides headercompression for upper layer data packets to reduce radio transmissionoverhead, security by ciphering the data packets, and integrityprotection of data packets. A PDCP context may indicate whether PDCPduplication is utilized for a unicast connection.

The RLC layer 812 provides segmentation and reassembly of upper layerdata packets, error correction through automatic repeat request (ARQ),and sequence numbering independent of the PDCP sequence numbering. AnRLC context may indicate whether an acknowledged mode (e.g., areordering timer is used) or an unacknowledged mode is used for the RLClayer 812. The MAC layer 810 provides multiplexing between logical andtransport channels. The MAC layer 810 is also responsible for allocatingthe various radio resources (e.g., resource blocks) in one cell amongthe UEs and for HARQ operations. A MAC context may enable, for example,a HARQ feedback scheme, resource selection algorithms, carrieraggregation, beam failure recovery, or other MAC parameters for aunicast connection. The physical layer 806 is responsible fortransmitting and receiving data on physical channels (e.g., withinslots). A PHY context may indicate a transmission format and a radioresource configuration (e.g., bandwidth part (BWP), numerology, etc.)for a unicast connection.

In the control plane, the radio protocol architecture for the UE andbase station is substantially the same for L1 806 and L2 808 with theexception that there is no SDAP layer in the control plane and there isno header compression function for the control plane. The control planealso includes a radio resource control (RRC) layer 818 in L3 and ahigher Non-Access Stratum (NAS) layer 820. The RRC layer 818 isresponsible for establishing and configuring signaling radio bearers(SRBs) and data radio bearers (DRBs) between the base station and theUE, paging initiated by the 5GC or NG-RAN, and broadcast of systeminformation related to Access Stratum (AS) and Non-Access Stratum (NAS).The RRC layer 818 is further responsible for QoS management, mobilitymanagement (e.g., handover, cell selection, inter-RAT mobility), UEmeasurement and reporting, and security functions. The NAS layer 820 isterminated at the AMF in the core network and performs variousfunctions, such as authentication, registration management, andconnection management.

In 5G NR networks, a base station may be an aggregated base station, inwhich the radio protocol stack is logically integrated within a singleRAN node, or a disaggregated base station, in which the radio protocolstack is logically split between a central unit (CU) and one or moredistributed units (DUs). The CU hosts the radio resource control (RRC),service data adaptation protocol (SDAP), and packet data convergenceprotocol (PDCP) layers that control the operation of one or more DUs.The DU hosts the radio link control (RLC), medium access control (MAC)and physical (PHY) layers. The CU may be implemented within an edge RANnode, while the one or more DUs may be co-located with the CU and/ordistributed throughout multiple RAN nodes that may be physicallyseparated from one another. Disaggregated base stations may be utilized,for example, in integrated access backhaul (IAB) networks.

FIG. 9 is a schematic diagram providing a high-level illustration of oneexample of an IAB network configuration 900 according to some aspects.In this illustration, a communication network 902, such as an IABnetwork, is coupled to a remote network 904, such as a main backhaulnetwork or mobile core network. In such an IAB network 902, the wirelessspectrum may be used for both access links and backhaul links. In someexamples, the wireless spectrum may utilize millimeter-wave (mmWave) orsub-6 GHz carrier frequencies.

The IAB network 902 may be similar to the radio access network 200 shownin FIG. 2 , in that the IAB network 902 may be divided into a numbercells 906, 908, 910, 912, and 914, each of which may be served by arespective IAB node 916, 918, 920, 922, and 924. Each of the IAB nodes916-924 may be a base station (e.g., a gNB), or other node that utilizeswireless spectrum (e.g., the radio frequency (RF) spectrum) to supportaccess for one or more UEs located within the cells 906-914 served bythe IAB nodes.

In the example shown in FIG. 9 , IAB node 916 communicates with UEs 926and 928 via wireless access links 930 and 932, IAB node 918 communicateswith UE 934 via wireless access link 936, and IAB node 922 communicateswith UE 938 via wireless access link 940. The IAB nodes 916-924 arefurther interconnected via one or more wireless backhaul links 942, 944,946, 948, 950, and 952. Each of the wireless backhaul links 942-952 mayutilize the same wireless spectrum (e.g., the radio frequency (RF)spectrum) as the access links 930-940 to backhaul access traffic to/fromthe remote network 904. This may be referred to as wirelessself-backhauling. Such wireless self-backhauling can enable fast andeasy deployment of highly dense small cell networks. That is, ratherthan requiring each new gNB deployment to be outfitted with its ownhardwired backhaul connection, the wireless spectrum utilized forcommunication between the gNB and UE may be leveraged for backhaulcommunication between any number of IAB nodes to form the IAB network902.

In the example shown in FIG. 9 , IAB node 916 communicates with IAB node920 via wireless backhaul link 942, IAB node 920 communicates with IABnode 922 via wireless backhaul link 944, IAB node 922 communicates withIAB node 924 via wireless backhaul link 946, IAB node 924 communicateswith IAB node 918 via wireless backhaul link 948, IAB node 918communicates with IAB node 916 via wireless backhaul link 950, and IABnode 918 communicates with IAB node 920 via wireless backhaul link 952.As shown in FIG. 9 , each IAB node 916-924 may be connected viarespective wireless backhaul links 942-952 to two or more other IABnodes for robustness.

Some or all of the IAB nodes 916-924 may also be connected via wiredbackhaul links (e.g., fiber, coaxial cable, Ethernet, copper wires,etc.) and/or microwave backhaul links. Thus, the IAB network 902 maysupport both wired/microwave and wireless backhaul traffic. At least oneof the IAB nodes (e.g., IAB node 924) may be a border IAB node, alsoreferred to herein as an IAB donor node, that also provides acommunication link 954 to the remote network 904. For example, the IABdonor node 924 may include a wired (e.g., fiber, coaxial cable,Ethernet, copper wires), microwave, or other suitable link 954 to theremote network 904.

To facilitate wireless communication between the IAB nodes 916-924 andbetween the IAB nodes 916-924 and the UEs served by the IAB nodes916-924, each IAB node 916-924 may be configured to operate as both ascheduling entity and a scheduled entity. Thus, an IAB node (e.g., IABnode 916) may utilize the same wireless spectrum to transmit accesstraffic to/from UEs and to then backhaul that access traffic to/from theremote network 904. For example, to backhaul access traffic to/from IABnode 918, IAB node 918 may communicate with IAB node 920 to transmitbackhaul access traffic via wireless backhaul link 942, IAB node 920 maycommunicate with IAB node 922 to transmit the backhaul access trafficvia wireless backhaul link 944, and IAB node 922 may communicate withIAB node 924 to transmit the backhaul access traffic via wirelessbackhaul link 946. In this example, IAB nodes 920 and 922 may eachoperate as both a scheduling entity and a scheduled entity to backhaulaccess traffic to/from IAB node 916. As such, communication between apair of IAB nodes may be individually scheduled by one of the IAB nodeswithin the pair.

In other examples, an IAB node may schedule wireless backhaulcommunications between other pairs of IAB nodes. For example, IAB node924 may operate as the scheduling entity for the IAB network 902, whileIAB nodes 916, 920, and 922 each operate as a scheduled entity tobackhaul access traffic to/from IAB node 916. In this example, IAB node924 may schedule wireless backhaul communications between each of thepairs of IAB nodes (e.g., between IAB node 916 and IAB node 920, betweenIAB node 920 and IAB node 922, and between IAB node 922 and IAB node924). As another example, IAB node 922 may operate as a schedulingentity to schedule wireless backhaul communications between IAB nodes916 and 920 and also between IAB node 920 and IAB node 922. IAB node 922may then operate as a scheduled entity to allow IAB node 924 to schedulewireless backhaul communications therebetween.

FIG. 10 is a schematic diagram illustrating an example of IAB nodefunctionality within an IAB network 1000. In the example shown in FIG.10 , an IAB node 1002 is shown coupled to a core network 1004 via awireline connection. This IAB node 1002 may be referred to herein as anIAB donor node, which may be, for example, an enhanced gNB includingfunctionality for controlling the IAB network 1000. In some examples,the IAB donor node 1002 may include a central unit (CU) 1006 and adistributed unit (DU) 1008. The CU 1006 is configured to operate as acentralized network node (or central entity) within the IAB network1000. For example, the CU 1006 may include radio resource control (RRC)layer functionality and packet data convergence protocol (PDCP) layerfunctionality to control/configure the other nodes (e.g., IAB nodes andUEs) within the IAB network 1000. Thus, the CU 1006 can be configured toimplement centralized mechanisms for handover decisions, topologychanges, routing, bearer mapping, UE security, and other suitableservices.

The DU 1008 is configured to operate as a scheduling entity to schedulescheduled entities (e.g., other IAB nodes and UEs) of the IAB donor node1002. For example, the DU 1008 of the IAB donor node 1002 may operate asa scheduling entity to schedule IAB nodes 1010 and 1012 and UEs 1014 and1016. Thus, the DU 1008 of the IAB donor node 1002 may schedulecommunication with IAB nodes 1010 and 1012 via respective backhaul linksand schedule communication with UEs 1014 and 1016 via respective accesslinks. In some examples, the DU 1008 may include the radio link control(RLC), medium access control (MAC), and physical (PHY) layerfunctionality to enable operation as a scheduling entity.

Each of the IAB nodes 1010 and 1012 may be configured as a Layer 2 (L2)relay node including a respective DU 1020 and a mobile termination (MT)unit 1018 to enable each L2 relay IAB node 1010 and 1012 to operate as ascheduling entity and a scheduled entity. For example, the MT unit 1018within each of the L2 relay IAB nodes 1010 and 1012 is configured tooperate as a scheduled entity that may be scheduled by the IAB donornode 1002. Each MT unit 1018 within the L2 relay IAB nodes 1010 and 1012further facilitates communication with the IAB donor node 1002 viarespective backhaul links. In addition, the DU 1020 within each of theL2 relay IAB nodes 1010 and 1012 operates similar to the DU 1008 withinthe IAB donor node 1002 to function as a scheduling entity to scheduleone or more respective scheduled entities (e.g., other IAB nodes and/orUEs) of the L2 relay IAB nodes 1010 and 1012.

For example, the DU 1020 of L2 relay IAB node 1012 functions as ascheduling entity to schedule communication with a UE 1022 via an accesslink, while the DU 1020 of L2 relay IAB node 1010 functions as ascheduling entity to schedule communication with the MT units 1018 of L2relay IAB nodes 1024 and 1026 via respective backhaul links and a UE1028 via an access link. Each of the L2 relay IAB nodes 1024 and 1026further includes a respective DU 1020 that functions as a schedulingentity to communicate with respective UEs 1030 and 1032.

Thus, in the network topology illustrated in FIG. 10 , the IAB donornode 1002, in combination with each of the L2 relay IAB nodes 1010,1012, 1024 and 1026, can collectively form a disaggregated base station.The disaggregated base station includes the CU 1006 and each of the DUs1008 and 1020 controlled by the CU 1006. The CU/DU functional split indisaggregated base stations can facilitate the realization oftime-critical services, such as scheduling, retransmission,segmentation, and other similar services in the DU 1008/1020, whilecentralizing the less time-critical services in the CU 1006. Inaddition, the CU/DU separation enables termination of externalinterfaces in the CU 1006 instead of each DU, and further supportscentralized termination of the PCDP to allow for dual connectivity andhandover between the different DUs of the disaggregated base station. Itshould be understood that disaggregated base stations may be implementedwithin networks other than IAB networks, and the present disclosure isnot limited to any particular type of network.

FIG. 11 illustrates an example of a disaggregated base station 1100according to some aspects. The disaggregated base station 1100 includesa CU 1102 and one or more DUs (three of which, 1104 a, 1104 b, 1104 c,are shown for convenience). Each DU 1104 a, 1104 b, and 1104 c supportsthe PHY, MAC, and RLC layers of the radio protocol stack. The CU 1102supports the higher layers, such as the PDCP and RRC layers. One of theDUs (e.g., DU 1104 a) may be co-located with the CU 1102, while theother DUs 1104 b and 1104 c may be distributed throughout a network. TheCU 1102 and DUs 1104 a, 1104 b, and 1104 c are logically connected viathe F1 interface, which utilizes the F1 Application Protocol (F1-AP) forcommunication of information between the CU 1102 and each of the DUs1104 a, 1104 b, and 1104 c and for establishing generic tunnelingprotocol (GTP) tunnels between the DU and CU for each radio bearer.

In some examples, the CU 1102 may be configured to perform operationsrelated to mobility (e.g., handover, dual connectivity, etc.),minimization of drive tests (MDT), and self-organizing networks (SON). ASON refers to mobile network automation and minimization of humanintervention in cellular/wireless network management. SON’s objectivesinclude: 1) bringing intelligence and autonomous adaptability intocellular networks; 2) reducing capital and operation expenditures; and3) enhancing network performances in terms of network capacity,coverage, offered service/experience, etc. SON aims at improvingspectral efficiency, simplifying management, and reducing the operationcosts of next generation radio access networks (RANs).

Drive tests are used for collecting data of mobile networks. This datais needed for the configuration and maintenance of mobile networks,e.g., with respect to network capacity optimization, network coverageoptimization, UE mobility optimization, and quality of service (QoS)verification. In order to execute drive tests, human effort is required.However, these measurements cover only a small piece of time andlocation of the network. MDT enables operators to utilize UEs to collectradio measurements and associated location information, in order toassess network performance while reducing the operation expendituresassociated with traditional drive tests. As such, MDT allows forstandard UEs to be used for collecting/recording measurements andreporting the measurements to the operators while traditional drivetests make use of high developed measurement equipment.

To facilitate mobility, SON, and MDT operations, the CU 1102 may need tohave knowledge of lower layer events and measurements undertaken by thevarious DUs 1104 a, and 1104 b, and 1104 c. Various aspects of thedisclosure provide enhancements to the F1-AP to enable measurement andevent reporting from the DUs 1104 a, 1104 b, and 1104 c to the CU 1102.The CU 1102 may configure each of the DUs 1104 a, 1104 b, and 1104 c toobtain values related to measurements or events and transmit measurementreports to the CU 1102 periodically or upon the occurrence of the event.Examples of DU measurements and events that may assist the CU 1102 inmobility, SON, MDT, and other CU-related operations may include RACHreports, uplink (UL) measurements, RLC protocol measurements, MACprotocol measurements, a respective load of each of the DUs 1104 a, 1104b, and 1104 c, detection of a remote interference measurement (RIM) orstrong UL interference measurement by one or more of the DUs 1104 a,1104 b, and 1104 c, and other suitable measurements or events.

FIG. 12 is a diagram illustrating exemplary signaling between a CU 1202and a DU 1204 of a disaggregated base station 1200 to commence DUmeasurement configuration and reporting. The signaling between the CU1202 and the DU 1204 may traverse the F1 interface. The CU 1202 maycorrespond, for example, to the CU 1006 within the IAB donor node 1002of FIG. 10 or CU 1102 shown in FIG. 11 . The DU 1204 may correspond, forexample, to any of the DUs illustrated in FIGS. 10 and/or 11 .

In the example shown in FIG. 12 , at 1206, the CU 1202 may send ameasurement request to the DU 1204 via the F1 interface. The measurementrequest may include a measurement configuration associated with at leastone value related to a measurement or event to be obtained by the DU1204. The measurement request may further include a reportingconfiguration for reporting the at least one value to the CU 1202. At1208, the DU 1204 may send a measurement response to the CU 1202confirming configuration of the DU 1204 in accordance with themeasurement configuration and the reporting configuration.

At 1210, the DU 1204 may obtain the at least one value in accordancewith the measurement configuration and generate a measurement reportincluding the at least one value in accordance with the reportingconfiguration. In some examples, the at least one value may include aRACH report, an uplink (UL) measurement, an RLC protocol measurement, aMAC protocol measurement, the DU load, a RIM detected indicator, astrong UL interference measurement detected indicator, or other valuescorresponding to other suitable measurements or events.

In some examples, the reporting configuration may configure the DU 1204for periodic reporting or event-based reporting of the measurementreport. Therefore, at 1212 and 1214, the DU 1204 may send either anevent-based DU measurement report or a periodic DU measurement report.

FIG. 13 is a diagram illustrating an example of a measurement request1300 for configuring measurement and event reporting by a DU accordingto some aspects. The measurement request 1300 includes a measurementconfiguration 1302 and a reporting configuration 1320 for themeasurement configuration 1302. The measurement configuration 1302 mayinclude at least one parameter 1304 associated with at least one valueto be reported by the DU. In addition, the measurement configuration1302 may include a measurement period 1306 over which the at least onevalue is obtained by the DU. The measurement period may include, forexample, a measurement window or other period of time over which the atleast one value (e.g., a measurement) may be obtained.

The measurement configuration 1302 may further include a filteringconfiguration 1308 for filtering the at least one value. In someexamples, lower layer measurements may fluctuate at a high rate, andtherefore, the filtering configuration may indicate a filter to be usedby the DU to reduce the fluctuation in the measurement. The measurementconfiguration 1302 may further include an optional F1-AP UE ID field1310. When the F1-AP UE ID field 1310 is included in the measurementconfiguration 1302, an identifier of a UE (UE ID) associated with themeasurement configuration 1302 is included in the F1-AP UE ID field1310. In this example, the measurement configuration is UE-specific(e.g., an F1-AP UE-associated service). As such, the measurement reportshould contain a UE-specific value (e.g., a value associated with orobtained by the UE), along with the UE ID. Otherwise, the measurementconfiguration 1302 is cell/DU specific.

The reporting configuration 1320 may configure the DU with periodicreporting 1322 a or event-based reporting 1322 b associated with themeasurement configuration 1302. When the reporting configuration 1320 isa periodic reporting configuration 1322 a, the reporting configuration1320 may include a periodicity 1324 of transmission of the measurementreport. For example, the periodicity 1324 of the reporting configuration1320 may instruct the DU to generate and transmit the measurement reportfor the measurement configuration 1302 at predefined intervals of time.The periodic reporting configuration 1322 a may further indicate one ormore selected parameters 1326 of the measurement configurationparameters 1304 to include in the measurement report. The selectedparameters 1326 may include all of the measurement configurationparameters 1304 or a subset of the measurement configuration parameters1304.

When the reporting configuration 1320 is an event-based reportingconfiguration 1322 b, the reporting configuration 1320 may include anevent-based indicator 1328 that provides an indication of an eventtriggering the measurement report. For example, the event-basedindicator 1328 may request the DU to generate and transmit themeasurement report upon the occurrence of the event corresponding to themeasurement configuration 1302. The event-based reporting configuration1322 b may further include one or more threshold(s) 1330 that may beused by the DU to determine whether to send the measurement report. Forexample, a threshold 1330 may indicate a certain number of occurrencesof the event before the UE generates and sends the measurement report.The event-based reporting configuration 1322 b may further indicate oneor more selected parameters 1332 of the measurement configurationparameters 1304 to include in the measurement report. The selectedparameters 1332 may include all of the measurement configurationparameters 1304 or a subset of the measurement configuration parameters1304.

In some examples, the at least one value includes a RACH report, and themeasurement configuration 1302 configures the DU to send the RACHreport. In addition, the reporting configuration 1320 may be anevent-based reporting configuration 1322 b that configures the DU tosend the RACH report upon completion of a successful RACH procedureperformed by a UE. For initial access and some other scenarios, the CUmay have knowledge of the RACH procedure and request the UE to transmitthe RACH report to the CU via RRC signaling. In these scenarios, theRACH report may be sent without requiring CU configuration of the DU.However, in other scenarios, such as loss of UL synchronization, noPUCCH resources, scheduling request failure, etc., the CU may not haveknowledge of the RACH procedure, and as such, the CU may configure theDU to transmit the RACH report using the measurement configuration 1302and associated reporting configuration 1320/1322 b.

For RACH reports, the at least one parameter 1304 included in themeasurement configuration 1302 may include one or more RACH parameters.For example, the RACH parameters 1304 may include one or more of a RACHindicator that indicates the report is a RACH report, a timing advancevalue provided to the UE during the RACH procedure, a detected power(e.g., RSRP or RSRQ of msg2 or msgB measured by the UE during the RACHprocedure), a RACH trigger indicating a reason (scenario) for initiatingthe RACH procedure (if DU known), a beam ID or SSB ID corresponding to abeam used for the RACH procedure, an uplink frequency band (e.g., SUL ornormal UL) used in the RACH procedure, a PRACH resource used formsg1/msgA in the RACH procedure, a RACH type (e.g., 2-step, 4-step,CFRA, CBRA, etc.), and a RAR window size of a RAR window configured formsgB of the RACH procedure (e.g., for optimization of the RAR window bythe CU to reduce latency).

Based on the reporting configuration 1320, the CU may configure the DUto generate a RACH report including respective values for each of theRACH parameters 1304 provided in the measurement configuration 1302 or asubset of the RACH parameters 1304 provided in the measurementconfiguration 1302, as indicated by the selected parameters 1332 in thereporting configuration 1320/1322 b. In this example, the reportingconfiguration 1320 may not include a threshold 1330 and the measurementconfiguration 1302 may not include a measurement period 1306 orfiltering configuration 1308 (e.g., these fields may be set to a nullvalue).

In some examples, the at least one value includes an uplink measurement,and the measurement configuration 1302 configures the DU to send theuplink measurement. In addition, the reporting configuration 1320 may bea periodic reporting configuration 1322 a or an event-based reportingconfiguration 1322 b that configures the DU to send the measurementreport either periodically or upon the occurrence of an event. In thisexample, the at least one parameter 1304 included in the measurementconfiguration 1302 includes at least one uplink measurement parameter.For example, the uplink measurement parameters 1304 may include at leastone of a sounding reference signal (SRS) measurement, a phase trackingreference signal (PTRS) measurement, an angle of arrival (AOA)measurement, an interference over thermal (IoT) measurement, a hybridautomatic repeat request (HARQ) retransmission rate, a maximum number ofHARQ retransmissions reached indicator, or a beam measurement report(e.g., RSRP/RSRQ/SINR per beam, as measured and reported by a UE).

In examples in which the uplink measurement parameter(s) 1304 includeone or more of an SRS measurement, a PTRS measurement, an AOAmeasurement, an IOT measurement, or a HARQ retransmission rate, themeasurement configuration 1302 may include a measurement period 1306.The reporting configuration 1320 may further include a periodicreporting configuration 1322 a indicating a periodicity 1324 andselected parameters 1326 of the uplink measurement parameters 1304 toinclude in the measurement report. In addition, for SRS measurements,PTRS measurements, AOA measurements, and IOT measurements, themeasurement configuration 1302 may further include a respectivefiltering configuration 1308 for one or more of the uplink measurementparameters 1304. In other examples, the reporting configuration 1320 mayinclude an event-based reporting configuration 1322 b instructing the DUto send the measurement report when the uplink measurement parameter1304 exceeds a threshold 1330.

In examples in which the uplink measurement parameter(s) 1304 includethe maximum number of HARQ retransmissions reached indicator or a beammeasurement report, the reporting configuration 1320 may be anevent-based reporting configuration 1322 b that instructs the DU totransmit the measurement report upon determining that the maximum numberof HARQ retransmissions for a UE has been reached or upon receiving abeam measurement report from a UE.

In some examples, the at least one value includes an RLC measurement andthe measurement configuration 1302 configures the DU to send the RLCmeasurement. In addition, the reporting configuration 1320 may be aperiodic reporting configuration 1322 a or an event-based reportingconfiguration 1322 b that configures the DU to send the measurementreport either periodically or upon the occurrence of an event. Forexample, the RLC measurement parameter(s) 1304 may include at least oneof a downlink RLC buffer occupancy, a first average number of RLCretransmissions per data radio bearer (DRB), a second average number ofRLC retransmissions per user equipment (UE), a third average number ofRLC retransmissions per cell, or a maximum number of RLC retransmissionsdetected indicator.

In examples in which the RLC measurement parameter(s) 1304 include oneor more of an RLC buffer occupancy or average number of RLCtransmissions per DRB/cell/UE, the measurement configuration 1302 mayinclude a measurement period 1306. The reporting configuration 1320 mayfurther include a periodic reporting configuration 1322 a indicating aperiodicity 1324 and selected parameters 1326 of the RLC measurementparameters 1304 to include in the measurement report. In other examples,the reporting configuration 1320 can include an event-based reportingconfiguration 1322 b instructing the DU to send the measurement reportwhen the RLC measurement exceeds a threshold 1330. In examples in whichthe RLC measurement parameter(s) 1304 include the maximum number of RLCretransmissions detected indicator, the reporting configuration 1320 maybe an event-based reporting configuration 1322 b that instructs the DUto transmit the measurement report upon determining that the maximumnumber of RLC retransmissions for a UE has been detected. In someexamples, the maximum number of RLC retransmissions detected may beindicated to the CU in a radio link failure (RLF) report withoutrequiring CU configuration of the DU.

In some examples, the at least one value includes a MAC measurement andthe measurement configuration 1302 configures the DU to send the MACmeasurement. For example, the MAC measurement parameter(s) 1304 mayinclude a beam failure recovery statistic. In this example, thereporting configuration 1320 may be a periodic reporting configuration1322 a or an event-based reporting configuration 1322 b that configuresthe DU to send the measurement report either periodically or upon theoccurrence of an event (e.g., the BFM statistic reaching a threshold1330).

In some examples, the at least one value includes a load of the DU andthe measurement configuration 1302 configures the DU to send the DUload. Here, the measurement parameter 1304 is the DU load, which mayhave an associated measurement period 1306. In this example, thereporting configuration 1320 may be a periodic reporting configuration1322 a or an event-based reporting configuration 1322 b that configuresthe DU to send the measurement report either periodically or upon theoccurrence of an event (e.g., the DU load reaching a threshold 1330).

In some examples, the at least one value includes an interferenceindicator and the measurement configuration 1302 configures the DU tosend the interference indicator. For example, the measurement parameter1304 may include a remote interference detected indicator or a stronguplink interference detected indicator. In this example, the reportingconfiguration 1320 may be an event-based reporting configuration 1322 bthat configures the DU to send the measurement report upon detectingremote interference or strong uplink interference.

FIG. 14 is a block diagram illustrating an example of a hardwareimplementation for a radio access network (RAN) node 1400 employing aprocessing system 1414. For example, the RAN node 1400 may be an IABdonor node, L2 relay IAB node, or other RAN node (e.g., base station,such as a gNB) forming at least a part of a disaggregated base station,as illustrated in any one or more of FIGS. 9-12 .

The RAN node 1400 may be implemented with a processing system 1414 thatincludes one or more processors 1404. Examples of processors 1404include microprocessors, microcontrollers, digital signal processors(DSPs), field programmable gate arrays (FPGAs), programmable logicdevices (PLDs), state machines, gated logic, discrete hardware circuits,and other suitable hardware configured to perform the variousfunctionality described throughout this disclosure. In various examples,the RAN node 1400 may be configured to perform any one or more of thefunctions described herein. That is, the processor 1404, as utilized ina RAN node 1400, may be used to implement any one or more of theprocesses and procedures described below.

In this example, the processing system 1414 may be implemented with abus architecture, represented generally by the bus 1402. The bus 1402may include any number of interconnecting buses and bridges depending onthe specific application of the processing system 1414 and the overalldesign constraints. The bus 1402 communicatively couples togethervarious circuits including one or more processors (represented generallyby the processor 1404), a memory 1405, and computer-readable media(represented generally by the computer-readable medium 1406). The bus1402 may also link various other circuits such as timing sources,peripherals, voltage regulators, and power management circuits, whichare well known in the art, and therefore, will not be described anyfurther. A bus interface 1408 provides an interface between the bus 1402and a transceiver 1410. The transceiver 1410 provides a communicationinterface or means for communicating with various other apparatus over atransmission medium (e.g., air). Depending upon the nature of theapparatus, a user interface 1412 (e.g., keypad, display, speaker,microphone, joystick, touchscreen) may also be provided. Of course, sucha user interface 1412 is optional, and may be omitted in some examples.

The processor 1404 is responsible for managing the bus 1402 and generalprocessing, including the execution of software stored on thecomputer-readable medium 1406. The software, when executed by theprocessor 1404, causes the processing system 1414 to perform the variousfunctions described below for any particular apparatus. Thecomputer-readable medium 1406 and the memory 1405 may also be used forstoring data that is manipulated by the processor 1404 when executingsoftware.

One or more processors 1404 in the processing system may executesoftware. Software shall be construed broadly to mean instructions,instruction sets, code, code segments, program code, programs,subprograms, software modules, applications, software applications,software packages, routines, subroutines, objects, executables, threadsof execution, procedures, functions, etc., whether referred to assoftware, firmware, middleware, microcode, hardware descriptionlanguage, or otherwise. The software may reside on a computer-readablemedium 1406.

The computer-readable medium 1406 may be a non-transitorycomputer-readable medium. A non-transitory computer-readable mediumincludes, by way of example, a magnetic storage device (e.g., hard disk,floppy disk, magnetic strip), an optical disk (e.g., a compact disc (CD)or a digital versatile disc (DVD)), a smart card, a flash memory device(e.g., a card, a stick, or a key drive), a random access memory (RAM), aread only memory (ROM), a programmable ROM (PROM), an erasable PROM(EPROM), an electrically erasable PROM (EEPROM), a register, a removabledisk, and any other suitable medium for storing software and/orinstructions that may be accessed and read by a computer. Thecomputer-readable medium 1406 may reside in the processing system 1414,external to the processing system 1414, or distributed across multipleentities including the processing system 1414. The computer-readablemedium 1406 may be embodied in a computer program product. By way ofexample, a computer program product may include a computer-readablemedium in packaging materials. Those skilled in the art will recognizehow best to implement the described functionality presented throughoutthis disclosure depending on the particular application and the overalldesign constraints imposed on the overall system.

In some aspects of the disclosure, the processor 1404 may includecircuitry configured for various functions. In examples in which the RANnode 1400 is an IAB donor node, the processor 1404 may include centralunit (CU) circuitry 1442 and distributed unit (DU) circuitry 1444. Inexamples in which the RAN node 1400 is an L2 relay IAB node, theprocessor 1404 may only include the DU circuitry 1444 (e.g., the CUcircuitry 1442 is omitted in this example). The CU circuitry 1442 mayfurther be configured to execute CU software 1452 included on thecomputer-readable medium 1406 to implement one or more of the functionsdescribed herein. In addition, the DU circuitry 1444 may further beconfigured to execute DU software 1454 included on the computer-readablemedium 1406 to implement one or more of the functions described herein.

The CU circuitry 1442 may further include DU measurement configurationcircuitry 1446, configured to configure the DU circuitry 1444 to obtainvalues related to measurements or events and transmit measurementreports (MRs) 1415 to the CU circuitry 1442 periodically or upon theoccurrence of the event. Examples of values that may be included in DUmeasurement reports 1415 may include RACH reports, uplink (UL)measurements, RLC protocol measurements, MAC protocol measurements, theDU load, RIM detection, strong UL interference detection, and othersuitable values related to measurements or events. The DU measurementconfiguration circuitry 1446 may further be configured to configureother DUs controlled by the CU circuitry 1442 in other L2 relay IABnodes via the transceiver 1410.

In some examples, the DU measurement configuration circuitry 1446 mayconfigure the DU circuitry 1444 and other DUs by sending a measurementrequest to the DU circuitry 1444 (and other DUs) via a logical F1interface. The measurement request may include a measurementconfiguration 1416 associated with at least one value related to ameasurement or event to be obtained by the DU circuitry 1444. Themeasurement request may further include a reporting configuration 1418for use by the DU circuitry 1444 in generating and sending a measurementreport 1415 reporting the at least one value to the CU circuitry 1442.The DU measurement configuration circuitry 1446 may configure the DUcircuitry 1444 (and other DUs) with multiple measurement configurations1416 and associated reporting configurations 1418, each associated witha different measurement report, which may be UE-specific orDU/cell-specific. The DU measurement configuration circuitry 1446 mayfurther be configured to execute DU measurement configuration software1456 included on the computer-readable medium 1406 to implement one ormore of the functions described herein.

In some examples, the DU circuitry 1444 may include DU measurementreporting circuitry 1448, configured to receive the measurement requestfrom the DU measurement configuration circuitry 1446 (or external DUmeasurement configuration circuitry when the RAN node 1400 is an L2relay IAB node). The DU measurement reporting circuitry 1448 may furtherbe configured to send a measurement response to the DU measurementconfiguration circuitry 1446 confirming configuration of the DUmeasurement reporting circuitry 1448 in accordance with the measurementconfiguration 1416 and the reporting configuration 1418.

The DU measurement reporting circuitry 1448 may further be configured toobtain the at least one value in accordance with the measurementconfiguration 1416 and generate a measurement report 1415 including theat least one value in accordance with the reporting configuration 1418.In some examples, the at least one value may include a RACH report, anuplink (UL) measurement, an RLC protocol measurement, a MAC protocolmeasurement, the DU load, a RIM detected indicator, or a strong ULinterference measurement detected indicator. In some examples, thereporting configuration 1418 may configure the DU measurement reportingcircuitry 1448 for periodic reporting or event-based reporting of themeasurement report 1415. Therefore, the DU measurement reportingcircuitry 1448 may send either an event-based DU measurement report or aperiodic DU measurement report 1415 to the CU circuitry 1442. The DUmeasurement reporting circuitry 1448 may further be configured toexecute DU measurement reporting software 1458 included on thecomputer-readable medium 1406 to implement one or more functionsdescribed herein.

FIG. 15 is a flow chart illustrating an exemplary process 1500 for a CUto configure DU measurement and event reporting according to someaspects. As described below, some or all illustrated features may beomitted in a particular implementation within the scope of the presentdisclosure, and some illustrated features may not be required forimplementation of all embodiments. In some examples, the process 1500may be carried out by the RAN node illustrated in FIG. 14 . The RAN nodemay include the CU and may further include a DU and/or be in wirelesscommunication with one or more DUs that collectively form adisaggregated base station. In some examples, the process 1500 may becarried out by any suitable apparatus or means for carrying out thefunctions or algorithm described below.

At block 1502, the CU may send a measurement request to a distributedunit (DU) of the disaggregated base station. The measurement request caninclude a measurement configuration associated with at least one valueto be obtained by the DU and a reporting configuration for reporting theat least one value to the CU.

For example, the at least one value can include a random access channel(RACH) report and the measurement configuration can include at least oneof a RACH indication, a timing advance, a detected power, a detectedsignal quality, a RACH trigger, a beam identifier, a synchronizationsignal block (SSB) identifier, an uplink frequency band, a physical RACH(PRACH) resource, a RACH type, or a random access response (RAR) windowsize. As another example, the at least one value can include an uplinkmeasurement, and the measurement configuration can include at least oneof a sounding reference signal (SRS) measurement, a phase trackingreference signal (PTRS) measurement, an angle of arrival measurement, aninterference over thermal (IoT) measurement, a hybrid automatic repeatrequest (HARQ) retransmission rate, a maximum number of HARQretransmissions reached indicator, or a beam measurement report.

As another example, the at least one value can include a radio linkprotocol (RLC) measurement, and the measurement configuration caninclude at least one of a downlink RLC buffer occupancy, a first averagenumber of RLC retransmissions per data radio bearer, a second averagenumber of RLC retransmissions per user equipment (UE), a third averagenumber of RLC retransmissions per cell, or a maximum number of RLCretransmissions detected indicator. As another example, the at least onevalue can include a medium access control (MAC) protocol measurement,and the measurement configuration can include at least a beam failurerecovery statistic.

In some examples, the measurement configuration includes at least oneparameter associated with the at least one value. In this example, thereporting configuration may indicate at least one selected parameter ofthe at least one parameter to include in the measurement report. In someexamples, the at least one value includes a load of the DU, a remoteinterference detected indicator, or a strong uplink interferencedetected indicator.

In some examples, the measurement configuration may further include atleast one of a measurement period for the at least one value or afiltering configuration for filtering the at least one value. In someexamples, the measurement configuration may further include anidentifier of a user equipment (UE) associated with the at least onevalue.

In some examples, the reporting configuration may be a periodicreporting configuration including a periodicity of the measurementreport, along with one or more selected parameters of the measurementconfiguration parameters to include in the measurement report. In someexamples, the reporting configuration may be an event-based reportingconfiguration including an event-based indicator requesting the DU tosend the measurement report upon an occurrence of an event correspondingto the measurement configuration. The event-reporting configuration mayfurther include one or more selected parameters of the measurementconfiguration parameters to include in the measurement report. In someexamples, the event-reporting configuration may further include at leastone threshold associated with the event. For example, the DU measurementconfiguration circuitry 1446 shown and described above in connectionwith FIG. 14 may send the measurement request to the DU via the F1interface.

At block 1504, the CU may receive a measurement response from the DUconfirming configuration of the DU in accordance with the measurementconfiguration and the reporting configuration. For example, the DUmeasurement configuration circuitry 1446 shown and described above inconnection with FIG. 14 may receive the measurement response from the DUvia the F1 interface.

At block 1506, the CU may receive a measurement report associated withthe at least one value from the DU in accordance with the measurementconfiguration and the reporting configuration. In some examples, themeasurement report includes the at least one value. In addition, themeasurement report may further include an identifier of a UE when themeasurement configuration indicates that the measurement report isUE-specific (e.g., the measurement configuration includes the identifierof the UE associated with the at least one value). Here, the UE may beserved by the disaggregated base station. For example, the CU circuitry1442 shown and described above in connection with FIG. 14 may receivethe measurement report.

FIG. 16 is a flow chart illustrating an exemplary process 1600 for DUmeasurement and event reporting according to some aspects. As describedbelow, some or all illustrated features may be omitted in a particularimplementation within the scope of the present disclosure, and someillustrated features may not be required for implementation of allembodiments. In some examples, the process 1600 may be carried out bythe RAN node illustrated in FIG. 14 . The RAN node may include the DUand further include a CU or be in wireless communication with a CU that,together with the DU, forms a disaggregated base station. In someexamples, the process 1600 may be carried out by any suitable apparatusor means for carrying out the functions or algorithm described below.

At block 1602, the DU may receive a measurement request from a centralunit (CU) of the disaggregated base station. The measurement request caninclude a measurement configuration associated with at least one valueto be obtained by the DU and a reporting configuration for reporting theat least one value to the CU.

In some examples, the at least one value can include a random accesschannel (RACH) report and the measurement configuration can include atleast one of a RACH indication, a timing advance, a detected power, adetected signal quality, a RACH trigger, a beam identifier, asynchronization signal block (SSB) identifier, an uplink frequency band,a physical RACH (PRACH) resource, a RACH type, or a random accessresponse (RAR) window size. As another example, the at least one valuecan include an uplink measurement, and the measurement configuration caninclude at least one of a sounding reference signal (SRS) measurement, aphase tracking reference signal (PTRS) measurement, an angle of arrivalmeasurement, an interference over thermal (IoT) measurement, a hybridautomatic repeat request (HARQ) retransmission rate, a maximum number ofHARQ retransmissions reached indicator, or a beam measurement report.

As another example, the at least one value can include a radio linkprotocol (RLC) measurement, and the measurement configuration caninclude at least one of a downlink RLC buffer occupancy, a first averagenumber of RLC retransmissions per data radio bearer, a second averagenumber of RLC retransmissions per user equipment (UE), a third averagenumber of RLC retransmissions per cell, or a maximum number of RLCretransmissions detected indicator. As another example, the at least onevalue can include a medium access control (MAC) protocol measurement,and the measurement configuration can include at least a beam failurerecovery statistic.

In some examples, the measurement configuration includes at least oneparameter associated with the at least one value. In this example, thereporting configuration may indicate at least one selected parameter ofthe at least one parameter to include in the measurement report. In someexamples, the at least one value includes a load of the DU, a remoteinterference detected indicator, or a strong uplink interferencedetected indicator.

In some examples, the measurement configuration may further include atleast one of a measurement period for the at least one value or afiltering configuration for filtering the at least one value. In someexamples, the measurement configuration may further include anidentifier of a user equipment (UE) associated with the at least onevalue.

In some examples, the reporting configuration may be a periodicreporting configuration including a periodicity of the measurementreport, along with one or more selected parameters of the measurementconfiguration parameters to include in the measurement report. In someexamples, the reporting configuration may be an event-based reportingconfiguration including an event-based indicator requesting the DU tosend the measurement report upon an occurrence of an event correspondingto the measurement configuration. The event-reporting configuration mayfurther include one or more selected parameters of the measurementconfiguration parameters to include in the measurement report. In someexamples, the event-reporting configuration may further include at leastone threshold associated with the event. For example, the DU measurementreporting circuitry 1448 shown and described above in connection withFIG. 14 may receive the measurement request from the CU via the F1interface.

At block 1604, the DU may obtain the at least one value in accordancewith the measurement configuration. For example, the DU measurementreporting circuitry 1448 shown and described above in connection withFIG. 14 may obtain the least one value.

At block 1606, the DU may send a measurement report associated with theat least one value to the CU in accordance with the reportingconfiguration. In some examples, the measurement report includes the atleast one value. In addition, the measurement report may further includean identifier of a UE when the measurement configuration indicates thatthe measurement report is UE-specific (e.g., the measurementconfiguration includes the identifier of the UE associated with the atleast one value). Here, the UE may be served by the disaggregated basestation. For example, the DU measurement reporting circuitry 1448 shownand described above in connection with FIG. 14 may send the measurementreport.

In one configuration, the disaggregated base station (e.g., DU and/or CUof the disaggregated base station) includes various means as describedin the present disclosure. In one aspect, the aforementioned means maybe the processor 1404 shown in FIG. 14 configured to perform thefunctions recited by the aforementioned means. In another aspect, theaforementioned means may be a circuit or any apparatus configured toperform the functions recited by the aforementioned means.

Of course, in the above examples, the circuitry included in theprocessor 1404 is merely provided as an example, and other means forcarrying out the described functions may be included within variousaspects of the present disclosure, including but not limited to theinstructions stored in the computer-readable medium 1406, or any othersuitable apparatus or means described in any one of the FIGS. 1, 2, 4-7,9-12, and/or 14 , and utilizing, for example, the processes and/oralgorithms described herein in relation to FIGS. 15 and 16 .

The processes shown in FIGS. 15 and 16 may include additional aspects,such as any single aspect or any combination of aspects described belowand/or in connection with one or more other processes describedelsewhere herein.

Aspect 1: A method of operation at a distributed unit (DU) of adisaggregated base station, comprising: receiving a measurement requestfrom a central unit (CU) of the disaggregated base station, themeasurement request comprising a measurement configuration associatedwith at least one value to be obtained by the DU and a reportingconfiguration for reporting the at least one value to the CU; obtainingthe at least one value in accordance with the measurement configurationat the DU; and sending a measurement report associated with the at leastone value from the DU to the CU in accordance with the reportingconfiguration.

Aspect 2: The method of aspect 1, wherein the at least one valuecomprises a random access channel (RACH) report and the measurementconfiguration comprises at least one of a RACH indication, a timingadvance, a detected power, a detected signal quality, a RACH trigger, abeam identifier, a synchronization signal block (SSB) identifier, anuplink frequency band, a physical RACH (PRACH) resource, a RACH type, ora random access response (RAR) window size.

Aspect 3: The method of aspect 1, wherein the at least one valuecomprises an uplink measurement, and the measurement configurationcomprises at least one of a sounding reference signal (SRS) measurement,a phase tracking reference signal (PTRS) measurement, an angle ofarrival measurement, an interference over thermal (IoT) measurement, ahybrid automatic repeat request (HARQ) retransmission rate, a maximumnumber of HARQ retransmissions reached indicator, or a beam measurementreport.

Aspect 4: The method of aspect 1, wherein the at least one valuecomprises a radio link protocol (RLC) measurement, and the measurementconfiguration comprises at least one of a downlink RLC buffer occupancy,a first average number of RLC retransmissions per data radio bearer, asecond average number of RLC retransmissions per user equipment (UE), athird average number of RLC retransmissions per cell, or a maximumnumber of RLC retransmissions detected indicator.

Aspect 5: The method of aspect 1, wherein the at least one valuecomprises a medium access control (MAC) protocol measurement, andwherein the measurement configuration comprises at least a beam failurerecovery statistic.

Aspect 6: The method of any of aspects 1 through 5, wherein themeasurement configuration comprises at least one parameter associatedwith the at least one value and the reporting configuration furtherindicates at least one selected parameter of at least one parameter toinclude in the measurement report.

Aspect 7: The method of aspect 1 or 6, wherein the at least one valuecomprises at least one of a load of the DU, a remote interferencedetected indicator, or a strong uplink interference detected indicator.

Aspect 8: The method of any of aspects 1 through 7, wherein themeasurement configuration further comprises at least one of ameasurement period for the at least one value or a filteringconfiguration for filtering the at least one value.

Aspect 9: The method of any of aspects 1 through 8, wherein thereporting configuration comprises at least one of a periodicity of themeasurement report or an event-based indicator requesting the DU to sendthe measurement report upon an occurrence of an event corresponding tothe measurement configuration.

Aspect 10: A method of operation at a central unit (CU) of adisaggregated base station, comprising: sending a measurement request toa distributed unit (DU) of the disaggregated base station, themeasurement request comprising a measurement configuration associatedwith at least one value to be obtained by the DU and a reportingconfiguration for reporting the at least one value to the CU; receivinga measurement response from the DU confirming configuration of the DU inaccordance with the measurement configuration and the reportingconfiguration; and receiving a measurement report associated with the atleast one value from the DU in accordance with the measurementconfiguration and the reporting configuration.

Aspect 11: The method of aspect 10, wherein the at least one valuecomprises a random access channel (RACH) report and the measurementconfiguration comprises at least one of a RACH indication, a timingadvance, a detected power, a detected signal quality, a RACH trigger, abeam identifier, a synchronization signal block (SSB) identifier, anuplink frequency band, a physical RACH (PRACH) resource, a RACH type, ora random access response (RAR) window size.

Aspect 12: The method of aspect 10, wherein the at least one valuecomprises an uplink measurement and the measurement configurationcomprises at least one of a sounding reference signal (SRS) measurement,a phase tracking reference signal (PTRS) measurement, an angle ofarrival measurement, an interference over thermal (IoT) measurement, ahybrid automatic repeat request (HARQ) retransmission rate, a maximumnumber of HARQ retransmissions reached indicator, or a beam measurementreport.

Aspect 13: The method of aspect 10, wherein the at least one valuecomprises a radio link protocol (RLC) measurement and the measurementconfiguration comprises at least one of a downlink RLC buffer occupancy,a first average number of RLC retransmissions per data radio bearer, asecond average number of RLC retransmissions per user equipment (UE), athird average number of RLC retransmissions per cell, or a maximumnumber of RLC retransmissions detected indicator.

Aspect 14: The method of aspect 10, wherein the at least one valuecomprises a medium access control (MAC) protocol measurement and themeasurement configuration comprises at least a beam failure recoverystatistic.

Aspect 15: The method of any of aspects 10 through 14, wherein themeasurement configuration comprises at least one parameter associatedwith the at least one value and the reporting configuration furtherindicates at least one selected parameter of the at least one parameterto include in the measurement report.

Aspect 16: The method of aspect 10 or 15, wherein the at least one valuecomprises at least one of a load of the DU, a remote interferencedetected indicator, or a strong uplink interference detected indicator.

Aspect 17: The method of any of aspects 10 through 16, wherein themeasurement configuration further comprises at least one of ameasurement period for the at least one value or a filteringconfiguration for filtering the at least one value.

Aspect 18: The method of any of aspects 10 through 17, wherein thereporting configuration comprises at least one of a periodicity of themeasurement report or an event-based indicator requesting the DU to sendthe measurement report upon an occurrence of an event corresponding tothe measurement configuration.

Aspect 19: The method of any of aspects 10 through 18, wherein themeasurement configuration comprises an identifier of a user equipment(UE) associated with the at least one value, wherein the UE is served bythe disaggregated base station.

Aspect 20: The method of aspect 19, wherein the measurement reportcomprises the identifier of the UE.

Aspect 21: An apparatus configured for wireless communication comprisinga transceiver, a memory, and a processor coupled to the transceiver andthe memory, the processor and the memory configured to perform a methodof any one of aspects 1 through 9 or aspects 10 through 20.

Aspect 22: An apparatus in a wireless communication network comprisingat least one means for performing a method of any one of aspects 1through 9 or aspects 10 through 20.

Aspect 23: A non-transitory computer-readable medium storingcomputer-executable code, comprising code for causing an apparatus in awireless communication network to perform a method of any one of aspects1 through 9 or aspects 10 through 20.

Several aspects of a wireless communication network have been presentedwith reference to an exemplary implementation. As those skilled in theart will readily appreciate, various aspects described throughout thisdisclosure may be extended to other telecommunication systems, networkarchitectures and communication standards.

By way of example, various aspects may be implemented within othersystems defined by 3GPP, such as Long-Term Evolution (LTE), the EvolvedPacket System (EPS), the Universal Mobile Telecommunication System(UMTS), and/or the Global System for Mobile (GSM). Various aspects mayalso be extended to systems defined by the 3rd Generation PartnershipProject 2 (3GPP2), such as CDMA2000 and/or Evolution-Data Optimized(EV-DO). Other examples may be implemented within systems employing IEEE802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra-Wideband (UWB),Bluetooth, and/or other suitable systems. The actual telecommunicationstandard, network architecture, and/or communication standard employedwill depend on the specific application and the overall designconstraints imposed on the system.

Within the present disclosure, the word “exemplary” is used to mean“serving as an example, instance, or illustration.” Any implementationor aspect described herein as “exemplary” is not necessarily to beconstrued as preferred or advantageous over other aspects of thedisclosure. Likewise, the term “aspects” does not require that allaspects of the disclosure include the discussed feature, advantage ormode of operation. The term “coupled” is used herein to refer to thedirect or indirect coupling between two objects. For example, if objectA physically touches object B, and object B touches object C, thenobjects A and C may still be considered coupled to one another—even ifthey do not directly physically touch each other. For instance, a firstobject may be coupled to a second object even though the first object isnever directly physically in contact with the second object. The terms“circuit” and “circuitry” are used broadly, and intended to include bothhardware implementations of electrical devices and conductors that, whenconnected and configured, enable the performance of the functionsdescribed in the present disclosure, without limitation as to the typeof electronic circuits, as well as software implementations ofinformation and instructions that, when executed by a processor, enablethe performance of the functions described in the present disclosure.

One or more of the components, steps, features and/or functionsillustrated in FIGS. 1-16 may be rearranged and/or combined into asingle component, step, feature or function or embodied in severalcomponents, steps, or functions. Additional elements, components, steps,and/or functions may also be added without departing from novel featuresdisclosed herein. The apparatus, devices, and/or components illustratedin FIGS. 1, 2, 4-7, 9-12, and 14 may be configured to perform one ormore of the methods, features, or steps described herein. The novelalgorithms described herein may also be efficiently implemented insoftware and/or embedded in hardware.

It is to be understood that the specific order or hierarchy of steps inthe methods disclosed is an illustration of exemplary processes. Basedupon design preferences, it is understood that the specific order orhierarchy of steps in the methods may be rearranged. The accompanyingmethod claims present elements of the various steps in a sample order,and are not meant to be limited to the specific order or hierarchypresented unless specifically recited therein.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but are to be accorded the full scope consistentwith the language of the claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. A phrase referring to“at least one of” a list of items refers to any combination of thoseitems, including single members. As an example, “at least one of: a, b,or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, band c. All structural and functional equivalents to the elements of thevarious aspects described throughout this disclosure that are known orlater come to be known to those of ordinary skill in the art areexpressly incorporated herein by reference and are intended to beencompassed by the claims. Moreover, nothing disclosed herein isintended to be dedicated to the public regardless of whether suchdisclosure is explicitly recited in the claims. No claim element is tobe construed under the provisions of 35 U.S.C. § 112(f) unless theelement is expressly recited using the phrase “means for” or, in thecase of a method claim, the element is recited using the phrase “stepfor.”

What is claimed is:
 1. A method of operation at a distributed unit (DU)of a disaggregated base station, comprising: receiving a measurementrequest from a central unit (CU) of the disaggregated base station, themeasurement request comprising a measurement configuration associatedwith at least one value to be obtained by the DU and a reportingconfiguration for reporting the at least one value to the CU, whereinthe measurement configuration further comprises a radio measurementstatistic associated with the at least one value to be reported by theDU; obtaining the at least one value in accordance with the measurementconfiguration at the DU; and sending a measurement report comprising theat least one value and the radio measurement statistic from the DU tothe CU in accordance with the reporting configuration.
 2. The method ofclaim 1, wherein the measurement report comprises a random accesschannel (RACH) report and the at least one value comprises at least oneof a RACH indication, a timing advance, a detected power, a detectedsignal quality, a RACH trigger, a beam identifier, a synchronizationsignal block (SSB) identifier, an uplink frequency band, a physical RACH(PRACH) resource, a RACH type, or a random access response (RAR) windowsize.
 3. The method of claim 1, wherein the at least one value comprisesan uplink measurement, the uplink measurement comprising at least one ofa sounding reference signal (SRS) measurement, a phase trackingreference signal (PTRS) measurement, an angle of arrival measurement, aninterference over thermal (IoT) measurement, a hybrid automatic repeatrequest (HARQ) retransmission rate, a maximum number of HARQretransmissions reached indicator, or a beam measurement report.
 4. Themethod of claim 1, wherein the at least one value comprises a radio linkprotocol (RLC) measurement, the RLC measurement comprising at least oneof a downlink RLC buffer occupancy, a first average number of RLCretransmissions per data radio bearer, a second average number of RLCretransmissions per user equipment (UE), a third average number of RLCretransmissions per cell, or a maximum number of RLC retransmissionsdetected indicator.
 5. The method of claim 1, wherein the at least onevalue comprises a medium access control (MAC) protocol measurement andthe radio measurement statistic comprises at least a beam failurerecovery statistic.
 6. The method of claim 1, wherein the measurementconfiguration comprises at least one parameter associated with the atleast one value to be reported by the DU and the reporting configurationfurther indicates at least one selected parameter of the at least oneparameter to include in the measurement report.
 7. The method of claim1, wherein the at least one value comprises at least one of a load ofthe DU, a remote interference detected indicator, or a strong uplinkinterference detected indicator.
 8. The method of claim 1, wherein themeasurement configuration further comprises a filtering configurationfor obtaining the at least one value.
 9. The method of claim 1, whereinthe reporting configuration comprises at least one of a periodicity ofthe measurement report or an event-based indicator requesting the DU tosend the measurement report upon an occurrence of an event correspondingto the measurement configuration.
 10. A disaggregated base stationwithin a wireless communication network, comprising: a memory; and aprocessor coupled to the memory, the processor being configured to:receive a measurement request from a central unit (CU) of thedisaggregated base station, the measurement request comprising ameasurement configuration of at least one value to be obtained by the DUand a reporting configuration for reporting the at least one value tothe CU, wherein the measurement configuration further comprises a radiomeasurement statistic associated with the at least one value to bereported by the DU; obtain the at least one value in accordance with themeasurement configuration at the DU; and send a measurement reportcomprising the at least one value and the radio measurement statisticfrom the DU to the CU in accordance with the reporting configuration.11. The disaggregated base station of claim 10, wherein the measurementreport comprises a random access channel (RACH) report and the at leastone value comprises at least one of a RACH indication, a timing advance,a detected power, a detected signal quality, a RACH trigger, a beamidentifier, a synchronization signal block (SSB) identifier, an uplinkfrequency band, a physical RACH (PRACH) resource, a RACH type, or arandom access response (RAR) window size.
 12. The disaggregated basestation of claim 10, wherein the at least one value comprises an uplinkmeasurement, the uplink measurement comprising at least one of asounding reference signal (SRS) measurement, a phase tracking referencesignal (PTRS) measurement, an angle of arrival measurement, aninterference over thermal (IoT) measurement, a hybrid automatic repeatrequest (HARQ) retransmission rate, a maximum number of HARQretransmissions reached indicator, or a beam measurement report.
 13. Thedisaggregated base station of claim 10, wherein the at least one valuecomprises a radio link protocol (RLC) measurement, the RLC measurementcomprising at least one of a downlink RLC buffer occupancy, a firstaverage number of RLC retransmissions per data radio bearer, a secondaverage number of RLC retransmissions per user equipment (UE), a thirdaverage number of RLC retransmissions per cell, or a maximum number ofRLC retransmissions detected indicator.
 14. The disaggregated basestation of claim 10, wherein the at least one value comprises a mediumaccess control (MAC) protocol measurement and the radio measurementstatistic comprises at least a beam failure recovery statistic.
 15. Thedisaggregated base station of claim 10, wherein the measurementconfiguration comprises at least one parameter associated with the atleast one value to be reported by the DU and the reporting configurationfurther indicates at least one selected parameter of the at least oneparameter to include in the measurement report.
 16. The disaggregatedbase station of claim 10, wherein the at least one value comprises atleast one of a load of the DU, a remote interference detected indicator,or a strong uplink interference detected indicator.
 17. Thedisaggregated base station of claim 10, wherein the measurementconfiguration further comprises a filtering configuration for obtainingthe at least one value.
 18. The disaggregated base station of claim 10,wherein the reporting configuration comprises at least one of aperiodicity of the measurement report or an event-based indicatorrequesting the DU to send the measurement report upon an occurrence ofan event corresponding to the measurement configuration.
 19. A method ofoperation at a central unit (CU) of a disaggregated base station,comprising: sending a measurement request to a distributed unit (DU) ofthe disaggregated base station, the measurement request comprising ameasurement configuration associated with at least one value to beobtained by the DU and a reporting configuration for reporting the atleast one value to the CU, wherein the measurement configuration furthercomprises a radio measurement statistic associated with the at least onevalue to be reported by the DU; receiving a measurement response fromthe DU confirming configuration of the DU in accordance with themeasurement configuration and the reporting configuration; and receivinga measurement report comprising the at least one value and the radiomeasurement statistic from the DU in accordance with the measurementconfiguration and the reporting configuration.
 20. The method of claim19, wherein the measurement report comprises a random access channel(RACH) report and the at least one value comprises at least one of aRACH indication, a timing advance, a detected power, a detected signalquality, a RACH trigger, a beam identifier, a synchronization signalblock (SSB) identifier, an uplink frequency band, a physical RACH(PRACH) resource, a RACH type, or a random access response (RAR) windowsize.
 21. The method of claim 19, wherein the at least one valuecomprises an uplink measurement, the uplink measurement comprises atleast one of a sounding reference signal (SRS) measurement, a phasetracking reference signal (PTRS) measurement, an angle of arrivalmeasurement, an interference over thermal (IoT) measurement, a hybridautomatic repeat request (HARQ) retransmission rate, a maximum number ofHARQ retransmissions reached indicator, or a beam measurement report.22. The method of claim 19, wherein the at least one value comprises aradio link protocol (RLC) measurement, the RLC measurement comprises atleast one of a downlink RLC buffer occupancy, a first average number ofRLC retransmissions per data radio bearer, a second average number ofRLC retransmissions per user equipment (UE), a third average number ofRLC retransmissions per cell, or a maximum number of RLC retransmissionsdetected indicator.
 23. The method of claim 19, wherein the at least onevalue comprises a medium access control (MAC) protocol measurement andthe measurement configuration comprises at least a beam failure recoverystatistic.
 24. The method of claim 19, wherein the measurementconfiguration comprises at least one parameter associated with the atleast one value to be reported by the DU and the reporting configurationfurther indicates at least one selected parameter of the at least oneparameter to include in the measurement report.
 25. The method of claim19, wherein the at least one value comprises at least one of a load ofthe DU, a remote interference detected indicator, or a strong uplinkinterference detected indicator.
 26. The method of claim 19, wherein themeasurement configuration further comprises a filtering configurationfor obtaining the at least one value.
 27. The method of claim 19,wherein the reporting configuration comprises at least one of aperiodicity of the measurement report or an event-based indicatorrequesting the DU to send the measurement report upon an occurrence ofan event corresponding to the measurement configuration.
 28. The methodof claim 19, wherein the measurement configuration comprises anidentifier of a user equipment (UE) associated with the at least onevalue, wherein the UE is served by the disaggregated base station. 29.The method of claim 28, wherein the measurement report comprises theidentifier of the UE.
 30. A disaggregated base station within a wirelesscommunication network, comprising: a memory; and a processor coupled tothe memory, the processor being configured to, at a central unit (CU) ofthe disaggregated base station: send a measurement request to adistributed unit (DU) of the disaggregated base station, the measurementrequest comprising a measurement configuration associated with at leastone value to be obtained by the DU and a reporting configuration forreporting the at least one value to the CU, wherein the measurementconfiguration further comprises a radio measurement statistic associatedwith the at least one value to be reported by the DU; receive ameasurement response from the DU confirming configuration of the DU inaccordance with the measurement configuration and the reportingconfiguration; and receive a measurement report comprising the at leastone value and the radio measurement statistic from the DU in accordancewith the measurement configuration and the reporting configuration.